Lang v The Queen

HIGH COURT OF AUSTRALIA

KIEFEL CJ,
GAGELER, GORDON, EDELMAN AND JAGOT JJ

THOMAS CHRIS LANG  APPELLANT

AND

THE QUEEN  RESPONDENT

Lang v The Queen

[2023] HCA 29

Date of Hearing: 12 May 2023
Date of Judgment: 11 October 2023

B57/2022

ORDER

Appeal dismissed.

On appeal from the Supreme Court of Queensland

Representation

R M O'Gorman KC with D M Caruana for the appellant (instructed by Fisher Dore Lawyers)

G J Cummings with N W Crane for the respondent (instructed by Office of the Director of Public Prosecutions (QLD))

Notice:  This copy of the Court's Reasons for Judgment is subject to formal revision prior to publication in the Commonwealth Law Reports.

CATCHWORDS

Lang v The Queen

Criminal Practice – Appeal – Unreasonable verdict – Independent assessment of evidence – Where appellant charged with and convicted of murder – Where appellant appealed conviction on ground that verdict unreasonable or could not be supported having regard to whole of evidence – Where deceased's injuries were either self‑inflicted or caused by appellant – Where only hypothesis consistent with appellant's innocence was deceased's injuries were self‑inflicted – Whether reasonable possibility upon whole of evidence that deceased died by suicide.

Evidence – Criminal trial – Admissibility – Expert opinion evidence – Where opinion evidence adduced from forensic pathologist that injuries occasioning death more likely inflicted by another person than self‑inflicted – Whether opinion based on expert knowledge – Whether wrong decision of question of law to admit evidence.

Words and phrases – "admissibility", "body of knowledge or experience", "expert evidence", "inadmissible", "independent assessment of the evidence", "miscarriage of justice", "opinion", "specialised knowledge", "training, study or experience", "unreasonable verdict", "wholly or substantially".

Criminal Code (Qld), ss 590AA, 668E.

1. KIEFEL CJ AND GAGELER J.   This is an appeal from a unanimous decision of the Court of Appeal of the Supreme Court of Queensland (McMurdo and Mullins JJA and Brown J)[1] which dismissed an appeal by the appellant against his conviction for murder following a trial by jury before Lyons SJA in that Supreme Court. We agree with Jagot J, for the reasons her Honour gives, that neither of the appellant's grounds of appeal to this Court has merit and that the appeal should therefore be dismissed.

   [1]R v Lang [2022] QCA 29.

2. The answer to the appellant's argument on the first ground of appeal is that the verdict of the jury was not unreasonable. The only hypothesis consistent with innocence was that Mrs Boyce stabbed herself to death. Taken as a whole, the evidence admitted at the trial was sufficient for the jury to exclude that hypothesis as unreasonable. The evidence would remain sufficient for the jury to exclude that hypothesis as unreasonable even if the evidence were taken to exclude the disputed opinion of Dr Ong that Mrs Boyce's wound was more likely to have been inflicted by another person than to have been self-inflicted.

3. The answer to the appellant's argument on the second ground of appeal is that admission of the disputed opinion of Dr Ong into evidence at the trial, over objection made by the appellant and ruled on by the trial judge in the pre-trial hearing, involved no wrong decision on any question of law. The opinion of Dr Ong was demonstrated by his evidence in chief at the trial to have been founded substantially on specialised knowledge of the interpretation of incised injuries acquired through long experience as a specialist forensic pathologist and through reading of literature on incised injuries within the specialised field of forensic pathology. Nothing in the evidence he gave in the pre-trial hearing or in cross-examination in the trial undermined that foundation.

4. We write to elaborate on the common law principles which bore on the admissibility of Dr Ong's opinion.

5. Expert evidence need not be opinion evidence. Evidence given by an expert sometimes involves nothing more than imparting expert knowledge and sometimes involves nothing more than giving a technical description of events and processes in which the expert was involved. Much of Dr Ong's evidence at the trial was evidence of the latter kind. It was evidence of what he did and saw in his capacity as a forensic pathologist when first he attended the scene of Mrs Boyce's death and when later he conducted her autopsy.

6. Subject to limited exceptions, however, opinion evidence can only be expert evidence. The reason lies in the nature of an opinion and in the nature of the curial process. An opinion is an inference drawn from observed and communicable data[2]. Within the curial process, data that has been observed is communicated to a court through the adducing of evidence. Drawing inferences from that evidence to make findings of fact is the function of the tribunal of fact. The tribunal of fact, whether a judge or a jury, can be expected to perform that fact-finding function forming their own opinion as to the inferences to be drawn from the evidence based on their own common knowledge and experience. Another person cannot usurp the fact-finding function of the tribunal of fact, and an opinion of another person based on nothing more than the common knowledge and experience of that person cannot assist the tribunal of fact in performing that function[3]. The tribunal of fact might at most be assisted in the performance of the function by being apprised of the opinion of another person – an expert – based on that person's specialised knowledge or experience. The probative value of evidence of an opinion that is based on specialised knowledge or experience then lies in the extent, if any, to which the opinion has the potential to assist the tribunal of fact in the process of drawing the requisite inferences for itself. 

   [2]Honeysett v The Queen (2014) 253 CLR 122 at 130-131 [21].

   [3]Smith v The Queen (2001) 206 CLR 650 at 655 [11].

7. That common law conception of the opinion of an expert having probative value only if and to the extent that the opinion can assist the tribunal of fact in forming its own opinion as to inferences to be drawn from evidence was the starting point and the dominant theme of the influential analysis in Makita (Australia) Pty Ltd v Sprowles[4]. The role of expert witnesses was explained at the commencement of that analysis in the following terms[5]:

   "Their duty is to furnish the Judge or jury with the necessary scientific criteria for testing the accuracy of their conclusions, so as to enable the Judge or jury to form their own independent judgment by the application of these criteria to the facts proved in evidence. The scientific opinion evidence, if intelligible, convincing and tested, becomes a factor (and often an important factor) for consideration along with the whole other evidence in the case, but the decision is for the Judge or jury."

   [4](2001) 52 NSWLR 705 at 729-745 [59]-[86].

   [5]Davie v Magistrates of Edinburgh 1953 SC 34 at 40. See Cross on Evidence, 13th Aust ed (2021) at 1143-1144 [29075] and the cases there noted.

8. The traditional approach of the common law to the admissibility of evidence of the opinion of an expert has been consistent with that conception of the probative value of evidence of the opinion of an expert lying in the extent, if at all, to which the opinion might assist the tribunal of fact to draw inferences from other evidence that has been adduced. The approach has been simultaneously to accept that "the opinion of witnesses possessing peculiar skill is admissible whenever the subject-matter of inquiry is such that inexperienced persons are unlikely to prove capable of forming a correct judgment upon it without such assistance" and to deny that "the opinions of witnesses can be received when the inquiry is into a subject-matter, the nature of which is not such as to require any peculiar habits or study in order to qualify a man to understand it"[6].

   [6]Smith's Leading Cases, 7th ed (1876), vol 1 at 577, quoted and applied in Clark v Ryan (1960) 103 CLR 486 at 491 and Burger King Corporation v Registrar of Trade Marks (1973) 128 CLR 417 at 421.

9. The traditional approach has come under strain as developments in specialised knowledge, especially in fields of behavioural science[7] and forensic science[8], have narrowed the subject-matters in respect of which it might continue to be asserted categorically and with confidence that common knowledge and experience provide so firm a foundation upon which to engage in fact-finding that the opinion of an expert could be of no assistance. This Court has emphasised that "it does not follow that, because a lay witness can describe events and behaviour, expert evidence is unavailable to explain those events and that behaviour"[9]. Nor does it follow that evidence of the opinion of an expert is unavailable to assist the tribunal of fact merely because the tribunal of fact, whether a judge or a jury, could be expected in the absence of that expert evidence to work out their own explanation for events and behaviour making use of nothing more than the common knowledge and experience that can be attributed to them.

   [7]eg Murphy v The Queen (1989) 167 CLR 94 at 111, 122, 130-131; Farrell v The Queen (1998) 194 CLR 286 at 292-293 [10]-[13], 299-301 [27]-[31], 320-322 [91]-[93].

   [8]eg Velevski v The Queen (2002) 76 ALJR 402 at 427 [156]; 187 ALR 233 at 268.

   [9]Murphy v The Queen (1989) 167 CLR 94 at 112.

10. Nonetheless, it remains a condition of the admissibility of evidence of the opinion of an expert at common law that the opinion be demonstrated to be based on specialised knowledge or experience of the expert that is beyond the common knowledge and experience attributable to the tribunal of fact. Only if that condition is satisfied can the opinion of the expert assist the tribunal of fact to form the requisite opinion of its own as to the inferences to be drawn from the evidence to make findings about disputed facts should the tribunal of fact be persuaded to accept and act upon the opinion[10].

    [10]Velevski v The Queen (2002) 76 ALJR 402 at 432-433 [177]-[182]; 187 ALR 233 at 274-275.

11. The parties were therefore correct in choosing to present their arguments on the appeal on the common understanding that the principles stated in Makita[11], and acknowledged and applied in Dasreef Pty Ltd v Hawchar[12] in the context of considering the admissibility of the opinion of an expert under the uniform evidence legislation, apply equally to the determination of the admissibility of an expert opinion at common law. Those principles require that, in order to satisfy the condition of admissibility that the opinion of an expert be demonstrated to be based on specialised knowledge or experience, the inference drawn by the expert which constitutes the opinion be supported by reasoning on the part of the expert sufficient to demonstrate that the opinion is the product of the application of the specialised knowledge of the expert to facts which the expert has observed or assumed.

    [11](2001) 52 NSWLR 705 at 743-744 [85].

    [12](2011) 243 CLR 588 at 604 [37].

12. The requirement for the opinion to be demonstrated to be the product of the application of the specialised knowledge of the expert is not absolute. In the terminology of the uniform evidence legislation, it is enough that the opinion be demonstrated to be based substantially on that specialised knowledge. Expression of the requirement in terms of substantiality recognises that specialised knowledge cannot be wholly divorced from common or ordinary knowledge and that it is "the added ingredient of specialised knowledge to the expert's body of general knowledge that equips the expert to give his or her opinion"[13]. The requirement will not be contravened by a process of reasoning on the part of an expert which involves using only those parts of the common or ordinary knowledge of the expert that are necessary for the expert to use in forming his or her opinion through the application of specialised knowledge[14].

    [13]Velevski v The Queen (2002) 76 ALJR 402 at 427 [158]; 187 ALR 233 at 268.

    [14]Velevski v The Queen (2002) 76 ALJR 402 at 429 [164]; 187 ALR 233 at 270.

13. Reasoning sufficient to demonstrate that the opinion formed by an expert is the product of the application of his or her specialised knowledge need not be limited to formal induction or deduction. Speculation, however, is not reasoning[15]. Nor is intuition. Writing extra-curially 90 years ago, in a passage adopted judicially in Makita[16] and many times elsewhere[17], Sir Owen Dixon observed that "courts cannot be expected to act upon opinions the basis of which is unexplained"[18]. He continued: "[h]owever valuable intuitive judgment founded upon experience may be in diagnosis and treatment, it requires the justification of reasoned explanation when its conclusions are controverted"[19].

    [15]HG v The Queen (1999) 197 CLR 414 at 428 [41].

    [16](2001) 52 NSWLR 705 at 730 [60].

    [17]eg R v Jenkins; Ex parte Morrison [1949] VLR 277 at 303, approved in Morrison v Jenkins (1949) 80 CLR 626 at 637, 641; R v Juric (2002) 4 VR 411 at 426 [19]; Samuels v Flavel [1970] SASR 256 at 260; Dasreef Pty Ltd v Hawchar (2011) 243 CLR 588 at 623 [92].

    [18]Dixon, "Science and Judicial Proceedings", in Crennan and Gummow (eds), Jesting Pilate, 3rd ed (2019) 124 at 130.

    [19]Dixon, "Science and Judicial Proceedings", in Crennan and Gummow (eds), Jesting Pilate, 3rd ed (2019) 124 at 130. See also Dasreef Pty Ltd v Hawchar (2011) 243 CLR 588 at 623 [92].

14. That is not to say that the permissible reasoning of an expert must be confined to matching an observed or assumed pattern of fact to patterns of fact encountered by the expert in the past. To adapt a comment made by the Supreme Court of the United States[20] in relation to the federal rule of evidence[21] which there permits expert testimony to be given in the form of an opinion if "scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue":

    "Trained experts commonly extrapolate from existing data. But nothing ... requires a ... court to admit opinion evidence that is connected to existing data only by the ipse dixit of the expert. A court may conclude that there is simply too great an analytical gap between the data and the opinion proffered."

    [20]General Electric Co v Joiner (1997) 522 US 136 at 146.

    [21]Rule 702 of the Federal Rules of Evidence.

15. Here, it is important to highlight a distinction touched on but not elaborated upon in Makita[22]. The distinction is between the present question as to whether a process of reasoning engaged in by an expert is sufficient to demonstrate that his or her opinion is the product of the application of specialised knowledge and the question of the extent to which a process of reasoning engaged in by an expert through the application of specialised knowledge is clear and convincing. Both questions can be described as going to the utility or value of the opinion[23].

    [22](2001) 52 NSWLR 705 at 743-745 [85]-[86].

    [23]Makita (Australia) Pty Ltd v Sprowles (2001) 52 NSWLR 705 at 732 [66], 733 [68]-[69], 735 [72].

16. However, it is the present question alone that goes inexorably to the "admissibility" of the opinion as distinct from its "weight"[24]. In addressing the present question of whether the opinion satisfies the condition of admissibility that the opinion be demonstrated to be based on specialised knowledge or experience of the expert, lack of cogency in so much of the reasoning as is found to involve application of specialised knowledge is not to the point: "the giving of correct expert evidence cannot be treated as a qualification necessary for giving expert evidence"[25].

    [24]Dasreef Pty Ltd v Hawchar (2011) 243 CLR 588 at 605 [42].

    [25]Commissioner for Government Transport v Adamcik (1961) 106 CLR 292 at 303; Dasreef Pty Ltd v Hawchar (2011) 243 CLR 588 at 623 [91].

17. The latter question – as to the cogency of reasoning involving the application of specialised knowledge – can also go to the admissibility of a resultant opinion. But that is only in so far as the degree of cogency of the reasoning bears on the extent to which the resultant opinion has the potential to assist the tribunal of fact in drawing requisite inferences from the evidence and so bears on the calculus to be undertaken by a court if and when the court is asked or required to consider whether the opinion should be excluded on the distinct ground[26] that the probative value of the opinion is outweighed by its prejudicial effect. Undertaking that calculus by assessing the probative value of the opinion having regard to the cogency of the reasoning proffered in evidence in support of it involves no departure from the now settled principle that the assessment of the probative value of evidence requires that evidence to be "taken at its highest": taking evidence at its highest involves making no assumption that the evidence in question is convincing[27]. The prejudicial effect which might in an appropriate case be required to be weighed against the probative value of an expert opinion has properly been recognised to be capable of including a risk that a jury might give the opinion more weight than it deserves by reason of a perception of the status of the expert – the so-called "white coat effect" – or by reason of difficulty in assessing information of a technical nature[28].

    [26]See Stephens v The Queen (1985) 156 CLR 664 at 669; Festa v The Queen (2001) 208 CLR 593 at 609-610 [51]. See also ss 135 and 137 of the Evidence Act 1995 (NSW) considered in Aytugrul v The Queen (2012) 247 CLR 170 at 186 [32].

    [27]See IMM v The Queen (2016) 257 CLR 300 at 314-315 [50].

    [28]See R v Sica [2013] QCA 247 at [130], referring to Edmond and Roberts, "Procedural Fairness, the Criminal Trial and Forensic Science and Medicine" (2011) 33 Sydney Law Review 359 at 380. See also Chin, Cullen and Clarke, "The Prejudices of Expert Evidence" (2022) 48(2) Monash University Law Review 59.

18. The latter question does not arise for consideration in the present appeal. The question is not within the scope of the second ground of appeal. The trial judge was not asked to exclude the opinion of Dr Ong on the ground that its probative value was outweighed by its prejudicial effect. No argument was put to the Court of Appeal or to this Court that failure to exclude the opinion on that ground constituted a miscarriage of justice.

19. The question for determination on the second ground of appeal therefore reduces to whether the process of reasoning disclosed by Dr Ong's testimony was sufficient to demonstrate that his opinion that Mrs Boyce's wound was more likely to have been inflicted by another person than to have been self-inflicted was the product of his application of the specialised knowledge of the interpretation of incised injuries which he undoubtedly had to the facts which he recounted as having observed when he attended the scene of Mrs Boyce's death and when later he conducted her autopsy.

20. There is, as Jagot J points out, some difficulty appreciating the evidence of Dr Ong merely from the transcript. It appears that English may not be his first language. From comments made by the trial judge to the jury, it appears that he was softly spoken. His sentence structure was difficult. Some of what he said was indistinct. For all of that, the overwhelming impression which emerges from reading the transcript is that of a professional and dispassionate forensic pathologist seeking to make sense of observed phenomena in respect of which neither his long experience nor his wide reading furnished an exact precedent.

21. Dr Ong said that his opinion was "based on" his "experience" as a forensic pathologist for about 25 years during which he had seen roughly two or three deaths from stab wounds a year and on the "literature" concerning the typical features of self-inflicted stab wounds and those of homicidal stab wounds. He also said in his evidence in chief in the pre-trial hearing that his opinion was "based on" his "logical sense of what happened". This expression was unfortunate in that it could be interpreted as Dr Ong saying that, in forming his opinion, he had drawn on some third source of background knowledge additional to his professional experience and the scientific literature. However, it is clear enough from his cross-examination in the pre-trial hearing that what he was saying was that he had engaged in a process of inductive reasoning which involved applying his knowledge of the interpretation of stab wounds to observed features of Mrs Boyce's wound to form a conclusion about which of the two scenarios was more likely. That is how his use of the expression was understood both by the trial judge[29] and by the Court of Appeal[30]. There is no reason to depart from that understanding.

    [29]R v Lang [2020] QSCPR 26 at [36].

    [30]R v Lang [2022] QCA 29 at [95].

22. From Dr Ong's more detailed evidence, it is apparent that two features of the wound he had observed were significant to the formation of his opinion that the wound was more likely caused by another person than self-inflicted. One was that there were multiple tracks through a single incision, indicating multiple movements of the blade (some four or five in total). The other and more specific feature concerned what Dr Ong considered must have occurred between the initial movements of the blade (the first two) and the later movements of the blade (the last two or three) to produce those multiple tracks. What he considered must have occurred was a partial withdrawal of the blade (of some 14 or 15 centimetres) followed by a rotation of the blade (of some 180 degrees), during which there would have been a slight delay, followed then by a reinsertion of the blade.

23. These were observations drawn from the nature of the wound itself. In considering them, Dr Ong was evidently comparing those features of this wound with the features of other wounds which he had seen and read about. The difficulty, which he acknowledged repeatedly, was that this wound did not fit a standard pattern. In his terminology, it was "odd".

24. What Dr Ong did not do well was explain why he found those features of the wound more consistent with stabbing by someone else than stabbing by the deceased. The pain that would have been involved in the partial withdrawal and rotation of the blade was part of the explanation but not the whole of the explanation. At least an equally important part of the explanation appears to have been that Dr Ong would have expected someone who was wanting to kill themself to plunge a knife along a single track rather than either to make multiple incisions or to move it around along multiple tracks within a single incision. This second part of the explanation lacked precision in the manner of its expression. But the appellant was incorrect to characterise it as having been based on Dr Ong's "personal, subjective view as to how a person may or may not act when attempting to die by suicide". Fairly read, it amounted to a process of inferential reasoning throughout which Dr Ong was engaging in a comparison of the features of this stab wound with what he had seen and read of the features of stab wounds made in the past by people who had wanted to kill themselves and by people who had been killed by others. The prior instances which Dr Ong said he had seen, and about which he said he had read, did not support the inference strongly, but neither did Dr Ong express his opinion strongly.

25. Absent a clearer explanation of Dr Ong's process of reasoning, his opinion about whether the features of the wound which he identified were more consistent with stabbing by someone else might legitimately have been thought to have carried little more weight than the opinion that could be expected to be formed by a layperson once apprised through the technical description by Dr Ong of the same features of the wound. That weakness might well have been thought to have gone to the admissibility of Dr Ong's opinion had the argument been advanced that its probative value was outweighed by its prejudicial effect.

26. That said, we cannot conclude that, in engaging in the process of reasoning which led to the formation of the opinion, Dr Ong did other than draw substantially on his specialised knowledge. Accordingly, the appeal should be dismissed.

    GORDON AND EDELMAN JJ.  

    Introduction

27. On 22 October 2015, Mrs Maureen Boyce died in her bed in her 20th-floor apartment at Kangaroo Point in Brisbane. She was 68 years old. The medical evidence was that the approximate time of death was between 1.45 am and 3.45 am. The cause of her death was blood loss from a stab wound to her abdomen from a knife. Only two people were in her apartment at the time of her death: Mrs Boyce and the appellant, Mr Lang. The appellant accepted at trial and before this Court that there were only two possibilities: either Mrs Boyce committed suicide, or she was murdered by the appellant.

28. The appellant was convicted at a trial before a judge and jury in which prejudicial evidence was admitted concerning the suicide rates of Australian women. The erroneous admission of that evidence led to that conviction being quashed on appeal[31]. The appellant was then retried before a judge and jury and convicted again. He was sentenced to life imprisonment. He appealed against that conviction on two grounds: that the verdict was unreasonable, and that an important aspect of the expert evidence given by Dr Ong, a forensic pathologist, expressing conclusions concerning the knife injury was inadmissible[32]. The Court of Appeal of the Supreme Court of Queensland (McMurdo and Mullins JJA and Brown J) dismissed the appeal[33]. The appellant, by special leave, appeals to this Court on the same two grounds.

    [31]See R v Lang [2019] QCA 289.

    [32]R v Lang [2022] QCA 29 at [9].

    [33]R v Lang [2022] QCA 29 at [7], [115], [116].

29. In oral submissions in this Court, senior counsel for the appellant disclaimed any submission that the admissibility of Dr Ong's evidence should affect the assessment of the first ground of appeal. In other words, it was accepted that the assessment of whether the verdict was unreasonable should proceed on the assumption that the entirety of Dr Ong's evidence was admissible.

30. In assessing whether the Court of Appeal was correct to conclude that the verdict of the jury was not unreasonable, this Court has the same duty as the Court of Appeal to engage in an "independent assessment of the evidence, both as to its sufficiency and its quality"[34]. It is the duty of an appellate court, and each of its members, when considering whether a verdict is unreasonable to examine the entirety of the record and properly to explain the conclusions in appropriate detail. That detail is considered below.

    [34]Dansie v The Queen (2022) 96 ALJR 728 at 732 [12]; 403 ALR 221 at 225, quoting SKA v The Queen (2011) 243 CLR 400 at 406 [14], in turn quoting Morris v The Queen (1987) 163 CLR 454 at 473. See also MFA v The Queen (2002) 213 CLR 606 at 614-615 [25], 623-624 [55]-[59]; SKA v The Queen (2011) 243 CLR 400 at 405-406 [11]-[14], 412 [37]-[38], 422 [80].

31. In broad summary, the prosecution case was circumstantial and, in addition to the fact that Mrs Boyce's death could only have been caused by Mrs Boyce or the appellant, relied particularly upon four significant matters.

32. First, there was evidence that although Mrs Boyce had long had suicidal ideation, this generally occurred when she was depressed and she would not act upon that ideation. There was evidence that she was not in a depressed state before she died, notably from her psychiatrist who saw her a day and a half before she died.

33. Secondly, the appellant had a motive to murder Mrs Boyce. He told police in his interviews that he loved her and had given up his medical practice to be with her. He thought that he was engaged to marry her and that she was coming to live with him in New Zealand. The appellant admitted that on the evening before her death she had argued with the appellant about fidelity and had mentioned a man, Mr Kenneth McAlpine, with whom the appellant thought she was having an affair.

34. Thirdly, and relatedly, Mrs Boyce's iPhone, her "lifeline", was thrown off the balcony but the appellant lied in his police interviews about the timing of when the iPhone was thrown off the balcony. He said that it was thrown off the balcony shortly before Mrs Boyce went to bed, variously expressing the time of that event as ranging between 9 pm and 9.45 pm. Around 9.30 pm, Mrs Boyce had spoken on the phone with her son and described herself as drowsy. She had taken prescription medicine and drunk a couple of glasses of wine. But forensic analysis of the iPhone showed that it could not have been thrown off the balcony until after midnight. In an eight-minute period around midnight the iPhone was unlocked by the use of Mrs Boyce's PIN code and text messages were opened including one from Mr McAlpine. A short phone call was also made with a silent 12-second message left on the voicemail of one of Mrs Boyce's contacts, Mr East, whom she had only met briefly, years ago.

35. Fourthly, expert evidence was given by Dr Ong about the nature of the knife wound. He said that although there was externally only a single stab wound, there were a number of internal tracks within the wound. He concluded after a lengthy analysis of the nature of the wound with an expression of the opinion that although he could not "completely eliminate" the possibility of a self-inflicted injury "it [was] more likely that [the] wound [was] caused by a ... different person".

36. The appellant did not call or give evidence at the trial. The defence case was that, as the appellant had said in his interviews with police, he had woken up in a separate bedroom around 5.30 am and discovered Mrs Boyce dead. The defence pointed to a number of matters consistent with suicide. Mrs Boyce had suffered from depression for many years with suicidal ideation. A day and a half before her death she had telephoned an acquaintance with whom she had not spoken for many years to say that she was very depressed and that she felt suicidal. A "protective" factor against suicide that her psychiatrist had described was the prospective birth of a grandchild, but Mrs Boyce had not told her psychiatrist that her daughter had told her that she would never see her grandchild.

37. On the evening of her death, Mrs Boyce had suffered a disappointment by discovering that prospective purchasers of her apartment were unlikely to purchase it. Mrs Boyce's treating psychiatrist agreed that the sale of the apartment was very important to her, and said that it was a protective factor that Mrs Boyce and Dr Boyce had been attempting to sell the apartment in order to reduce their financial burden and get Dr Boyce down to Brisbane so that he would not have to work too much. The possibility that the prospective purchasers would not buy the apartment would have weakened the protective factor but would not necessarily have made her more suicidal.

38. The defence also relied on the forensic evidence—and the absence of forensic evidence—at the scene. The knife was found in Mrs Boyce's abdomen and the tips of the fingers of her left hand were "just in contact" with the handle of the knife. No fingerprints were located on the handle of the knife and the only DNA recovered from the handle of the knife was consistent with that of Mrs Boyce. The appellant's DNA was not detected anywhere on Mrs Boyce's body, apart from on her breasts. The prosecution accepted that this could be explained by her being in a relationship with the appellant and his statements that there had been some interaction between them earlier that night, or by contact with her while she was on the bed. A forensic medical examination of the appellant and his clothing revealed no injury or any forensic evidence relevant to the death of Mrs Boyce. There was no blood found anywhere in the apartment other than the bed and a couple of drops beside the bed, and there was no evidence that blood had been cleaned up.

39. For the purpose of DNA and other forensic testing, the police took swabs from Mrs Boyce's body, the handle of the knife, blood on the carpet in the bedroom, the rims and contents of the wine glasses, a red/brown stain on a plant pot on the balcony, and the tap and sink hole (including a "U-bend" pipe) in the master ensuite. That targeted testing was based in part upon prior examination of the whole apartment both visually and by a blood-screening chemical or a presumptive test (referred to as "TMB"). A confirmatory test for blood called HemaTrace was also conducted on items that presumptively tested positive for blood (such as the stain on the pot, the tap, sink hole and U-bend), but that confirmatory testing showed no positive results for blood.

40. The evidence was that, although the injury may have taken up to five seconds to inflict, the significant blood loss occurred as a result of a much slower seepage over time. Mrs Boyce would likely have been conscious for between five and 15 minutes from the time the wound was inflicted, experiencing a physiological fight or flight response if she had been stabbed by the appellant. But the scene was not consistent with any movement or a struggle. The saturation stain on the fitted bottom sheet under Mrs Boyce was the result of the slow release of blood from the wound over a period of time with minimal movement. There was no evidence that Mrs Boyce attempted to make a phone call from the landline phone beside her bed. Neither Mrs Boyce nor the appellant had any injuries consistent with a struggle. And it was not put to any of the expert witnesses at trial, nor ever suggested in any submissions on appeal to the Court of Appeal or in this Court, that this could be explained on the basis that Mrs Boyce might have experienced a physiological "freeze" response.

41. In the circumstances of this case, the critical question is whether, on an examination of the whole of the evidence, the prosecution failed to exclude as a reasonable hypothesis that Mrs Boyce committed suicide. That question is finely balanced and we have struggled with the answer to it. The only proper approach, and that which we have adopted, is a dispassionate, objective and accurate assessment of all the evidence and argument. When that approach is taken, and the case is viewed as a whole, the better view is that the prosecution did exclude beyond reasonable doubt the hypothesis that Mrs Boyce committed suicide. For the reasons explained in detail below, therefore, the verdict of the jury was not unreasonable.

42. A significant aspect of the reasoning in support of the conclusion that the verdict was not unreasonable, however, is the expert evidence of Dr Ong concerning the likelihood that Mrs Boyce's injury was inflicted by another person. In this Court, and in the Court of Appeal, the appellant did not submit that an assessment of whether the verdict was unreasonable should take place without regard to Dr Ong's evidence. But, in relation to the second ground of appeal it must be accepted that there was no basis in expertise that was exposed by Dr Ong for his opinion on the critical issue that went to the very heart of the matters in dispute. Dr Ong's evidence on this point should have been excluded and the second ground of appeal should be upheld. There should be a retrial.

    The core narrative from the evidence at trial

    Background to 21 October 2015

43. Mrs Boyce was born in 1947. Around 1974, Mrs Boyce commenced a relationship with Dr Boyce, who is a general practitioner of medicine. They married in 1976. Dr Boyce was aware that Mrs Boyce had mental health issues involving anxiety and that Mrs Boyce saw a psychiatrist irregularly. Around 1979 or 1980, on a two-week trip by herself to the United States to see a friend, Mrs Boyce met the appellant. A couple of months later she told Dr Boyce that she had met the appellant and was going to travel to Texas to see more of the appellant. The appellant was at medical school at that time. He later became a doctor.

44. During Mrs Boyce's extended period in the United States, she remained in contact with Dr Boyce. He flew to the United States for a medical conference in San Francisco. Dr Boyce met Mrs Boyce after the conference and spent four to six weeks travelling in the United States with her, after which he returned to Australia. At that time, Dr Boyce was aware that she was in a relationship with the appellant.

45. In 1979 or 1980, several months after Dr Boyce's visit, Mrs Boyce had planned to return to Australia. But she was hospitalised and became too ill to return to Australia. Dr Boyce flew to Texas to bring her home. While Dr Boyce was in the United States, the appellant telephoned Dr Boyce, they met for lunch, and the appellant took Dr Boyce on a tour of Houston.

46. Mrs Boyce returned to Australia with Dr Boyce around 1980 and they had two children, a son who was born in 1981 some months after her return from the United States, and a daughter who was born in 1985. From the time of Mrs Boyce's return to Australia she had been taking anti-depressants. Around 1995, after the death of Mrs Boyce's mother and a family feud, Mrs Boyce became depressed. When she was suffering the symptoms of depression, she would not go out or take care of her appearance, she did not want to see people, and could not sleep. She was hospitalised for a period of time and she remained under psychiatric care and medicated for her psychiatric illness from that time onwards. Mrs Boyce's son, a doctor, described her psychiatric illness as "bipolar depression". He said that he saw her once or twice in a manic phase and on other occasions in a depressive phase.

47. Dr Spelman, Mrs Boyce's treating psychiatrist for many years, described her illness as a bipolar disorder with a capacity for her mood to be abnormally low or abnormally high. In the almost 15 years that he treated her before her death he had seen her in the depressed state where he described her as "pervasively sad and unhappy" with reduced self-care, not showering regularly, having trouble getting out of bed, and having difficulty sleeping. When she was in an elevated state she was energetic, highly social, quite reckless with her spending, and would tend to avoid seeing Dr Spelman. In addition, he described her as having a longstanding borderline personality disorder that led her to be more impulsive and unstable than someone who merely suffered from bipolar disorder. Her moods could go up and down on a daily basis.

48. From around 1999 or 2000, Mrs Boyce had a relationship, which developed into a sexual relationship, with Mr McAlpine, who was the gardener and handyman for the family home. Their sexual relationship ended in 2002 or 2003 when he moved to New South Wales. But they stayed in touch including after Mr McAlpine had moved back to Brisbane.

49. From around 2002, Dr Boyce was working in Cairns as a general practitioner. Mrs Boyce and the children would visit Dr Boyce in Cairns and he would make trips to Brisbane where Mrs Boyce and the children were living. But in late 2002, Mrs Boyce purchased, in her name, an apartment at Kangaroo Point when the family was not in a financial position to do so. Dr Boyce assumed financial responsibility for the mortgage repayments. From that point, Dr Boyce lived in Cairns for work and would fly in and out of Brisbane to see his family. The family would also travel to Cairns to stay with him during school and university holidays, and later, when the children were no longer at home, Mrs Boyce would go up to Cairns by herself. Dr Boyce also paid the living expenses for Mrs Boyce and the children.

50. During 2013 and 2014, for about 18 months, Mrs Boyce "lived fairly exclusively" in Cairns with Dr Boyce and her son who was then working in Cairns Hospital.

51. At the beginning of 2013, Mrs Boyce got in touch again with the appellant who was living in New Zealand. She did so following discussions with her son who Mrs Boyce had previously suggested was the biological child of the appellant. Her son was interested in obtaining a United States passport and asked Mrs Boyce to get in touch with the appellant. Mrs Boyce told her son that the appellant had told her that the appellant would consider assisting with a passport if she travelled to see the appellant in New Zealand, which she did.

52. In mid-to-late 2013, the appellant travelled to Brisbane and had dinner with Mrs Boyce and her son. Mrs Boyce's son did not remain in direct contact with the appellant after that dinner, but Mrs Boyce began to travel to New Zealand to see him. Mrs Boyce told her son that she was considering leaving Dr Boyce for the appellant, but later she said that she would not leave Dr Boyce.

53. In 2013, Dr Boyce discovered that Mrs Boyce had travelled to New Zealand to see the appellant. He discovered this after receiving a letter or email from the appellant thanking Dr Boyce for letting Mrs Boyce travel to New Zealand to help the appellant who had been suffering from depression. But Dr Boyce was not then aware of the regularity of Mrs Boyce's trips to New Zealand, or the appellant's trips to Brisbane, which continued through 2014 and 2015.

54. During 2014, Dr Boyce returned to Brisbane with Mrs Boyce because he had been diagnosed with prostate cancer which was aggressive and required surgery in November 2014. Around that time, Mrs Boyce was having major problems with depression which were contributed to by Dr Boyce's cancer. From late November, Mrs Boyce was treated with electroconvulsive therapy as a day patient in hospital for three days a week for several weeks, and then was admitted to hospital in late December 2014 to finish off the course of treatment. She was discharged in January 2015. Mrs Boyce subsequently travelled back to Cairns to be with Dr Boyce because she was in such a depressive phase that she was unable to care for herself.

55. On 16 February 2015, Mrs Boyce travelled to New Zealand and stayed there for 32 days. While there, Mrs Boyce sent a text message apologising to her daughter who was upset that she had travelled to New Zealand to see the appellant. Not long after her return, Mrs Boyce was hospitalised for pneumonia for a number of days. Mrs Boyce attended consultations with Dr Spelman on 2 April and 27 April 2015, and then was hospitalised on 30 April 2015 for another course of treatment for her depression. It was noted in her admissions summary that the stressors that were operative at the time were her husband's illness and her daughter's upcoming wedding. It was important to Mrs Boyce to get well for her daughter's wedding, which was at the end of May 2015.

56. Dr Spelman's notes from around that time included a description of Mrs Boyce's intermittent suicidal ideation, which he explained to the jury was preoccupation with thinking about ending one's life. There was other evidence that Mrs Boyce was experiencing suicidal ideation around that time. While Mrs Boyce was in Cairns with Dr Boyce in 2015, and suffering from serious depression, she told him that she would jump off the balcony or slip off the back of the ferry and disappear. She texted the appellant on 7 June 2015, telling him that she had wanted to commit suicide by jumping off the back of a cruise boat. He responded the same day, saying "Mimi, what's harder. The effort it takes to get here or to continue on the brink of suicide and flirting w it daily?".

57. Mrs Boyce's suicidal ideation was not isolated. Dr Spelman described her as expressing suicidal ideation whenever she was depressed. He said that her suicidal ideation was not something coming and going on a daily basis when she was not depressed. In her discussions with Dr Spelman, Mrs Boyce's suicidal ideation never progressed to suicidal intent or planning. She had remarked to Dr Boyce and her son on a number of occasions over the years that she was thinking about suicide. She had told Dr Boyce many times that she felt so bad she wished that she were dead. It would be fairly common for her to speak of jumping off the balcony. On an occasion when Mrs Boyce was in Brisbane and Dr Boyce was working in Cairns, she had made suicidal remarks to Dr Boyce and Dr Boyce telephoned the police and ambulance who attended the apartment. Dr Boyce gave evidence that when they arrived, "they came in and found her happily sitting down, having some supper and watching a TV show", and that she was upset with him for "dobbing her in" and wasting their time. On one occasion when she had spoken to her son about suicide, around 2009, her son had found her standing on the balcony peering over and when she saw him approach she moved her leg as if to stand on a chair. Her son encouraged her to get down and she remarked that she "would never go ahead with it" and that she wouldn't leave the children but that she "just didn't like the way [she] was feeling".

58. In June or July 2015, following the marriage of their daughter, Dr Boyce and Mrs Boyce engaged an agent to sell the Kangaroo Point apartment so that they could buy a smaller apartment in the same block where their son also purchased an apartment. Dr Boyce said that the plan was for them to move back in together in Brisbane and he would "semi-retire[]".

59. Mrs Boyce's condition improved in late July 2015. One day in late July she went to the hairdressers and a nail salon, and bought new clothes before going out to dinner with Dr Boyce. Dr Boyce said that after that night her mood had changed.

60. During that period, the appellant regularly emailed Mrs Boyce. On 23 July 2015, the appellant emailed Mrs Boyce with details of a property that they could buy together in New Zealand. On 13 August 2015, he emailed her an invitation to an upcoming festival in Tauranga, New Zealand, and said that "hopefully [Tauranga] will be [her] home by then".

61. In August 2015, Mrs Boyce returned to Brisbane from Cairns to facilitate the sale of the apartment and see friends. On 3 September 2015, Mrs Boyce and the appellant had a text exchange where he asked the current amount of her Brisbane mortgage and said he was "[j]ust thinking of our future options". She responded, "What about your options?", to which he replied "OUR options" and said "[w]e have much to discuss". She asked him to call her and said "I want to talk to you now or else I'm cancelling my trip to NZ".

62. On 11 September 2015, she travelled from Brisbane to New Zealand and stayed there for 14 days. At the time that Mrs Boyce left, Dr Boyce was still living and working in Cairns. He became concerned when he was unable to contact Mrs Boyce and he asked his son to check on Mrs Boyce. His son told Dr Boyce that Mrs Boyce was on her way to New Zealand to see the appellant. His son referred to a post on Mrs Boyce's Facebook page to that effect. Dr Boyce was extremely upset because he had been unaware of the continuing contact between Mrs Boyce and the appellant. Dr Boyce posted an offensive message on Mrs Boyce's Facebook page. Regular daily contact between Dr Boyce and Mrs Boyce ceased and did not resume until a week after Mrs Boyce returned from New Zealand. Mrs Boyce's son texted her while she was in New Zealand that "Dad's very upset that you would spend his money to go over there and now he can't pay his tax bill" and asked her to "[s]top spending all this money that dad can't afford".

63. On 20 September 2015, Mrs Boyce's daughter, who described herself as "heavily pregnant" and "very emotional" at the time, texted Mrs Boyce saying that Mrs Boyce had "ruined [their] family", that she wanted nothing to do with Mrs Boyce again, and that Mrs Boyce would never meet her grandson. Mrs Boyce sent her daughter texts in the weeks which followed but received no reply. Mrs Boyce's daughter said that it was not unusual for them not to be speaking with each other for some time.

64. In September 2015, the relationship between Mrs Boyce and Dr Boyce soured further. On 20 September, Dr Boyce texted Mrs Boyce to say, "[i]f u sell then lang can help u clear it out", to which she responded, "Lang has got nothing to do with it". A few days later, Dr Boyce texted Mrs Boyce to say that she "would be best to stay permanently in n.z.". Mrs Boyce replied "Stop playing games!!! I'm coming back to Brisbane", "I'm finished with him" and "What have you been saying to [our daughter]? She sent me the nastiest text message."

65. On 25 September 2015, Mrs Boyce returned to Brisbane from New Zealand. She texted the appellant, "Miss you already darling", and he responded, "I LO[V]E YOU DARLING!!!!!!!!!". On 26 September 2015, Mrs Boyce contacted Mr McAlpine, with whom she had been in regular contact, to invite him to watch a Riverfire performance in Brisbane that evening from her apartment. He went to her apartment where they had a few drinks and talked into the night.

66. On 28 September 2015, Mrs Boyce told Dr Boyce that she had finished with him and that she wanted a divorce. She must have previously discussed the possibility of divorce with the appellant because in a text message to her on 26 September 2015 the appellant said that he had sent her information for a divorce. Dr Boyce said that the idea of a divorce lasted only a day or two.

67. At around that time, after Mrs Boyce had returned from New Zealand, she entered into a "cash contract" for the purchase of an apartment in the block next to their apartment in Kangaroo Point. Dr Boyce considered that they could not afford to buy the apartment. He told the agent that the contract should be annulled on the grounds of Mrs Boyce's mental health. Ultimately, however, Dr Boyce agreed to sign a contract which was subject to finance rather than unconditional. Finance was not obtained. Dr Spelman said he believed that Mrs Boyce was in a manic or hypomanic phase when she signed the contract for the apartment.

68. On 29 September 2015, Dr Boyce tried to call Dr Spelman's rooms to book an appointment. Dr Spelman was on leave until mid-October. His clinical practice coordinator recorded in her notes that Dr Boyce had concerns about Mrs Boyce's mental state because she was manic, unsettled, had "want[ed] to put a contract on a luxury unit", had stopped taking her medication and was refusing to attend an appointment with Dr Spelman's locum psychiatrist.

69. On 1 October 2015, the clinical practice coordinator again spoke to Dr Boyce and recorded that "Things are settling. Talking with [Dr Boyce] and son now. (Had been refusing to do so). Recommencing medications". Dr Boyce told the jury that he and Mrs Boyce had started talking to each other again in early October, the animosity between them had "mellowed", and she had said that she was having nothing more to do with the appellant. On 1 October 2015, Mrs Boyce texted the appellant and invited him to come and visit her in Brisbane. The next day, she addressed a message to him wishing him a happy birthday "To the love of my life, Tom".

70. On the same day, Mrs Boyce went to a lunch with two friends. Her friends both said that Mrs Boyce said she was happy she was going to become a grandmother. One of the friends said that Mrs Boyce said that her relationship with the appellant was over, while the other friend remembered her saying that she was ending the relationship. One friend said that Mrs Boyce did not say that the appellant was coming to Brisbane to visit her; the other friend could not recall.

71. On 6 October 2015, the appellant travelled from New Zealand to Brisbane. He had been encouraged by Mrs Boyce to come to Brisbane to visit, and he stayed with Mrs Boyce in her Kangaroo Point apartment. About five days later Mrs Boyce texted her son and said that the appellant had arrived the day before and that the appellant was severely depressed. Mrs Boyce asked her son not to tell Dr Boyce. Two days later she texted her son again and said "I'm trying to get Tom to go back to NZ ASAP. He just sleeps all day and drinks 2 or 3 bottles [of] red wine at night after I've gone to bed!!".

72. On 15 October 2015, Mrs Boyce texted Mr McAlpine to say that her "kiwi friends are still staying" with her so she could not see Mr McAlpine for another week. She wrote:"[t]hey won't leave. I think I will have to be rude and ask them to leave next week. I've had enough."

73. On the weekend of 16 October to 18 October 2015, Mrs Boyce went to a musical with her son. Her son described her as being in high spirits and happy to be away from the appellant for the evening. Mrs Boyce told her son that she was sick of the appellant staying with her and had been trying to get rid of him but had not yet directly asked him to leave. She took a photo with her son and asked him to post it on Facebook so that people would know that she was not depressed and was going out again. Her son said that a couple of days later she told him that she had asked the appellant to leave but that the appellant had replied that he did not have any money to buy a plane ticket back to New Zealand.

74. On 19 October 2015, at 5.28 am, Mrs Boyce sent a text message to Dr Boyce saying, "I feel all depressed again. Up at 3 am today."

75. On 20 October 2015, at 10.21 am, Mrs Boyce telephoned an acquaintance, Ms Neilson, who Mrs Boyce had not spoken to for years. Ms Neilson said that Mrs Boyce sounded "very, very down, very out—very depressed". Mrs Boyce said that Dr Boyce was returning to Brisbane from Cairns because he had stomach cancer, but was continuing to work as a doctor because they had financial problems. Ms Neilson also said that Mrs Boyce told her "I'm just very, very—very, very depressed" and "I've tried to commit suicide" and that she felt suicidal. Then Mrs Boyce abruptly ended the call with a reference to a knock at the door or another call. Ms Neilson said that she thought the call went for "probably about a minute", however it was an admitted fact at trial that the call lasted for nearly eight minutes.

76. At 1.30 pm that afternoon, Dr Spelman saw Mrs Boyce. Mrs Boyce attended with the appellant who waited in the corridor outside Dr Spelman's rooms. She was reasonably well dressed and was not expressing any depressive symptoms. Mrs Boyce told Dr Spelman that her relationship with her husband was strained but that her daughter was pregnant and the baby was due the following February. She said that she had been elevated and had been waking up very early, which Dr Spelman believed was related to her restarting her medications that she had stopped in Cairns when she had become elevated: "[t]hat was reflecting a process, she had gone back onto them". He was aware, because of the records taken by his clinical practice coordinator while he was on leave, that Dr Boyce had called the clinic with concerns on 29 September 2015 that Mrs Boyce was manic and had stopped taking medication, but that he had called again on 1 October 2015 to indicate that "[t]hings are settling" and that Mrs Boyce had recommenced medication. Dr Spelman recorded in his notes on 20 October 2015 that the apartment had not been sold, Dr Boyce and Mrs Boyce had the same agent, they had run out of advertising money, and they had not had any offers. She said she was talking to Dr Boyce every day and he was managing okay with his health. Dr Spelman did not make notes recording his discussion with Mrs Boyce about the appellant, but he said he had a reasonably good recollection. Mrs Boyce said words to the effect that she was in a relationship again with the appellant and that they were about to go to the shopping centre across the road to organise a ticket for him back to New Zealand, although the appellant was not aware at that time that he was going back alone. Dr Spelman made an appointment to see Mrs Boyce in six days' time, as he was concerned how things were going to go given that she had not indicated to the appellant why they were going to the shopping centre.

77. On 20 October 2015, a one-way ticket to New Zealand, departing on 27 October 2015, was purchased in the appellant's name. Police inquiries with the travel centre confirmed that the appellant booked the ticket on his credit card.

    The events of 21 and 22 October 2015

78. On 21 October 2015, at around 11 am, Mrs Boyce telephoned Mr McAlpine and left a message on his voicemail. Mrs Boyce said that she had people visiting from New Zealand but that there was one person whom she could not get rid of, and, in what Mr McAlpine described as "almost ... a light-hearted way", she suggested that Mr McAlpine could help get rid of that person.

79. In the afternoon, Mrs Boyce went to the movies with the appellant. At around 6.30 pm, Mrs Boyce and the appellant went out to dinner because her real estate agent was going to show prospective buyers through the Kangaroo Point apartment. Dr Boyce said that these prospective purchasers had showed more promise than anyone in the preceding few months and, from what he and Mrs Boyce had been told, were "quite keen" to buy the apartment.

80. Following the inspection of the Kangaroo Point apartment that evening, the real estate agent telephoned Mrs Boyce to inform her that the prospective buyers may not purchase the apartment. The agent said that Mrs Boyce was disappointed because "she was very keen to see these buyers place an offer".

81. After speaking with the agent, Mrs Boyce telephoned Dr Boyce and said that the people who had viewed the apartment were not going to buy it and that she wanted to give the property to another agent to sell.

82. At about 7.53 pm, Mrs Boyce called the real estate agent. The agent said that they spoke about other ways to try and generate an offer by providing a bank valuation to the prospective buyers.

83. Around 8.00 pm, Mrs Boyce telephoned Dr Boyce again. Dr Boyce said that Mrs Boyce told him that the prospective buyers had said they wanted to see the bank valuation that had been done a few months earlier, and if they were satisfied with it, they would proceed to purchase the property. She asked Dr Boyce to provide her with the valuation that he had obtained from the bank so that she could show it to prospective purchasers. She said words to the effect that it was very important that Dr Boyce get the valuation to her or the agent the next morning.

84. Shortly after her phone conversation with Dr Boyce, Mrs Boyce telephoned her friend, Ms Russo. She told Ms Russo that she was stressed because a potential buyer had changed their mind about the purchase of the apartment and that she really wanted to sell the apartment. They talked about the bank valuation and discussed dropping the sale price. Mrs Boyce told Ms Russo that she would see Ms Russo on 29 October 2015 at the birthday party for Ms Russo's mother. Ms Russo followed that phone conversation with a text message urging Mrs Boyce to stay positive.

85. At around 9.30 pm, Mrs Boyce returned a phone call that she had received from her son. She told him that she and the appellant had been to a restaurant and that they had had a lovely meal. Her son said that she sounded "in high spirits" and "a little tipsy" so he asked her if she was okay. She replied that she had had a couple of glasses of wine with dinner and that she had taken her medication which had made her very drowsy. She said that she was very excited because they had a buyer for the apartment. Mrs Boyce's son could hear the television on in the background.

86. Between 10.34 pm and 10.49 pm, the computer in the office area in the apartment was accessed. A number of websites were visited, including an adult website. Adult websites had also been accessed on the computer on other dates.

87. Just before midnight, Mrs Boyce's mobile phone (an iPhone) was unlocked with the use of a PIN code. The recovered iPhone memory from that night, recorded by way of screenshots that the iPhone automatically takes and saves at various intervals when certain activities occur, did not provide a screenshot of everything viewed. But a screenshot was taken which showed Mr McAlpine's contact details, and a later one showed a text message from Mr McAlpine dated 18 May 2015. Around 12.04 am, a call was made from Mrs Boyce's iPhone to Mr East leaving a 12-second message on his voicemail, with no person speaking. Mr East was asleep and did not answer the call. Mr East had never given Mrs Boyce his phone number and did not know her well, although he was in contact with her son. He was a Facebook friend of Mrs Boyce and his settings allowed his friends to see his phone number. His phone number was in Mrs Boyce's phone contacts.

88. The time of Mrs Boyce's death was roughly estimated at between 1.45 am and 3.45 am that morning. The electronic records and CCTV footage established that no one accessed the apartment between when Mrs Boyce and the appellant returned home from dinner at 7.23 pm the evening before, and when the paramedics and police arrived the next morning. Mrs Boyce's iPhone must have been thrown from the apartment at some point after midnight. It was found by police in the vicinity of the building the next day.

89. At 5.32 am on 22 October 2015, the appellant made a 000 call from the landline phone in Mrs Boyce's bedroom next to her bed. He told the operator that he had just woken up and had found his fiancée dead. He said that he was not sure what happened. He said that Mrs Boyce had a knife in her abdomen with one of her hands on it and that she had been distraught the night before and that he had slept in another room. The appellant told the operator that he was a doctor and that he knew she was dead. He said that it did not look like there had been any forced entry to the apartment and that the wound was "self-induced", from what he could tell.

90. The paramedics and the police arrived at the apartment at 6.06 am. Mr Weijers, an advanced care paramedic, entered the bedroom. Mrs Boyce was lying in her bed. Mr Weijers moved a pillow from on top of Mrs Boyce to assess her. He was unable to detect a pulse and observed other signs of death, so he did not provide any further medical care.

91. Mrs Boyce died from the loss of blood caused by a stab wound from one of her kitchen knives which had a blade that was 19.5 cm long. She was lying on her back but partially on her right-hand side. The entirety of the blade and part of the handle had been pushed into her abdomen. She was partially covered by a flat sheet and a duvet. The blade was embedded in her body through the flat sheet. The tip of the blade had penetrated the entire body and was protruding out the back. Her left hand was on the handle of the knife and her right hand was under a pillow behind her head. There was blood on the knife handle, on the area around the wound and on Mrs Boyce's left hand, but not on her right hand. Her blood alcohol level at the time of death was found to be 0.049 and the levels of drugs indicated therapeutic or sub-therapeutic levels of her medication: diazepam (a sedative); nordiazepam (a metabolite of diazepam); amlodipine (to deal with hypertension); olanzapine and venlafaxine (to lessen anxiety). The sheets were tucked in under one side of the bed, consistent with her having slept alone.

92. In the lounge room, outside the bedroom where Mrs Boyce was found dead, there was a half-empty bottle of red wine on a coffee table with two wine glasses: one was half-full and the other "just had dregs in the bottom of the glass". In the kitchen there was an empty wine glass and a tin of coffee on the counter. In the dining area there was a coffee cup and some change.

93. Mrs Boyce left the entirety of her estate to her children.

    The appellant's interviews with police

94. The appellant was interviewed a number of times on 22 October 2015. The transcripts of those interviews were before the Court. Many of his statements in those interviews were corroborated by other evidence. For example, his statements concerning: the history of his relationship with Mrs Boyce; their reconnection in 2013; trips that they had made together; his relationship with Mrs Boyce's son; his account of Mrs Boyce's mental health; his account of Mrs Boyce's relationship with her daughter; and his account of his and Mrs Boyce's movements on 21 October. There was also a number of discrepancies in statements that he made in the interviews including: he said there was "weird texting" going on but there was no evidence that Mrs Boyce sent any text messages on the evening of 21 October; he appeared to suggest that he was able to read out the names of contacts from his phone despite claiming earlier that the phone had been locked by Mrs Boyce while he was in the bathroom, such that he could no longer access it; at one point he seemed to say that he had a coffee when he woke up but at another he said he did not; and he initially said he did not recall which of two balconies the phone was thrown off, but then remembered during his second formal interview.

95. The appellant's first interaction with the police when they arrived at the Kangaroo Point apartment on 22 October 2015 was recorded. The appellant was asked to describe the events of the previous night. He explained that he had been out to dinner with her and that she had heard the news that her apartment was not going to be sold and he then said:

    "So ah, so she was very distraught last night. Drunk a lot of alcohol, took some pills, she's had psychiatric history in the past, E-C-T a couple of times. Her husband's a doctor. Her son, our son that we had together thirty-two years ago, he t-, he, he ah, he's in the building here on the sixth floor. I would have called him and/or her husband or anybody, but my s-, phone's been blocked. I can't even access it. Last night, she was very distraught. She got into my phone for something, saw a call from my aunty who's eighty years old, and thought there was something going on, was very upset. Um, I tried to explain it was my eighty old aunt who was taking care of my mother. I'm just trying s-, trying to keep the sequence here. At about 9 o'clock, she took her cell phone and just winged it off the balcony somewhere, said she was going to bed and wanted me, for the first time this has ever happened, asked me to sleep at the other end of the house. I--"

96. The appellant said that Mrs Boyce went to bed at around 9.30 pm and that he went to bed probably at around 11.00 pm. He said he went in and "gave her a kiss goodnight, tucked her in and that was it. I haven't seen her since till just this." When he woke up he "went to the bathroom, made a cup of coffee, went in to give her a kiss, and that's what I found". He called emergency services using the landline phone in her bedroom. He said that she had "got into my phone somehow" and blocked it so that he couldn't use it.

97. When the police asked about alcohol and pills, the appellant said that Dr Boyce would know best, and that "[u]m, over the last year, I think she's had E‑C‑T ... twice. She saw [a] psychiatrist a few days ago. Three, three [or] four days ago she woke up and said she felt like she was gonna die, wanted to die, but then by the end of the day she was fine. And in fact, when she went and saw her psychiatrist, she was in pretty good shape." He later explained that the day before she saw the psychiatrist she had woken up at 3.00 am in the morning, "she's been waking up crazy hours, said she felt like she was, wanted to die. By the afternoon, she was, said he [sic] felt fine ... [s]he came out [of the appointment with Dr Spelman the following day] saying that he was happy with how well she was doing". The appellant said Mrs Boyce had had suicidal issues in the past, but not that he had seen recently. The appellant said they had been making salad "the other day" and she had commented on the knives, "[s]he just said they're, you can cut your finger off, she said, like that. They're so sharp."

98. Of the evening before, the appellant said "I had no idea she was that distraught, but I knew something was wrong when she threw her cell phone off the balcony ... she went berserk over a, a text from my aunt ... [s]he thought I was having an affair". He said that "she had been, ah she may have been, been having another affair on the side for all I know ... there was some weird texting going on last night and she alluded to something, but I couldn't put two and two together, but when I asked about it, she just, you know, got very agitated ... That's the last time I saw her, was like 9.30, 9.45, something like that." He said that she had taken her regular medicines, and he thought some Valium and alcohol, the previous night. He also said that "[s]he was really disappointed that the people didn't buy her place", that she had taken it "really personally" and that "[s]he called a couple of friends last night and asked what to do, 'cause she c-, she was frustrated". The throwing of the iPhone off the balcony was "unusual behaviour". He wasn't sure which balcony she threw her iPhone off—"there's like five balconies here ... it was either this one or that one".

99. The appellant explained that "[s]omething had come up during the day about, that she might have been having an a-, ... even though she's married to Graham ... [a]nd we were engaged to get married". He explained that she was still married, but that Mrs Boyce and Dr Boyce had been separated for "she said at least twenty years or something". The appellant said that he and Mrs Boyce had a son together, but that he didn't know about it until two years ago. He said that they had just got a ticket for the appellant to go back to New Zealand the following week.

100. The appellant provided further details in the two formal interviews at the police station later that morning and that afternoon. He told the police that he and Mrs Boyce had planned to get married before Christmas, and that she was going through a divorce process with her husband. He said that she had been suicidal in the past but had been "pretty good" until the morning a few days before, when she woke up at 2.00 or 3.00am and said she wanted to die again. By noon she suddenly seemed fine. The appellant said that she went to an appointment with her psychiatrist the next day and "[s]he came out like [her psychiatrist] patted her on the back and said you're doing great. I said well didn't you tell him that you wanted [to] die like you know only twenty four hours before that. And she said no I didn't mention it." He believed that she might have spoken to Dr Boyce about it; she talked to Dr Boyce a couple of times, every day. He repeated that, when they were chopping up a salad some days earlier, she had said something about "how expensive the knives were and how super sharp they were and how you can cut off fingers and things very easily".

101. The appellant said Mrs Boyce was in "great spirits" at dinner until the real estate agent called her to tell her the prospective buyers thought the place was too big for them. He said she took it like a personal insult and he tried to keep calming her down. The appellant suggested that she get the place "spiffed up" and not be there, so she didn't have to set it up every single day. The appellant said Mrs Boyce agreed and said she would come to New Zealand in a couple of weeks but that the appellant had to buy her a ticket because she was out of money and had "run out all her credit cards".

102. The appellant said that he and Mrs Boyce left the restaurant at 7.00 pm and returned to her Kangaroo Point apartment. In the period of around two hours between returning home and Mrs Boyce going to bed, Mrs Boyce made some phone calls and started watching a television show called "Bachelorette". He said that Mrs Boyce had asked him to record the "Bachelorette" show for her, which he thought had started airing while they were still out for dinner. When they got home, they put on the recording but had the sound turned off because Mrs Boyce kept making phone calls. She spoke on the phone to Ms Russo, Dr Boyce and the real estate agent. He thought that the show finished around 9.30 pm.

103. While the "Bachelorette" show was on television, and the appellant was in the bathroom, Mrs Boyce saw a text message on his phone from "Laurel", who was his aged aunt. He said that when he came out of the bathroom his phone (which was a basic flip phone without a PIN code) had been locked and was asking for something that he described as an "OPKU" code (an investigative computer analyst was later able to access information on the SIM card for the appellant's mobile phone after a police officer obtained a PUK code from the mobile carrier in New Zealand).

104. The appellant said that Mrs Boyce would not accept that "Laurel" was his aged aunt, and that Mrs Boyce began listing off names of people who were in the appellant's phone contacts. She "[i]mplied there was an affair or something going on" and he observed to the police that "she may have been actually having another affair besides me for all I know. It had come up earlier in the day.". He thought that "there might have been some guilt involved or something but it was really strange the way she reacted about the cell phone".

105. The appellant later explained that the thing that had come up earlier in the day was that Mrs Boyce had said to him: "I'm going to hook back up again with that Kenneth guy". "Kenneth" (Mr McAlpine) had apparently been a "fix it guy, handy man" and they had had affairs on and off. She said "well I'm going to call Kenneth and have him [INDISTINCT] fix up the place". In his interviews with police, the appellant said that that comment was "like a little stab you know?" and later said again "[i]t was a real stab in the back in a way, oh terrible thing to say". He said there was "a [jealousy] factor" building up from earlier in the day and a distrust. "She knew I knew about Kenneth ... she told me they haven't had contact in months and then she said I just got a hold of Kenneth and he's going to come fix everything". He said he thought she had been texting Mr McAlpine and that something was still going on, and "why she was getting suspicious about me is the way of putting off me thinking about her". At various points in his interviews the appellant said that he thought that Mrs Boyce may have been having an affair. He also said that his "heart went out" to Dr Boyce, and "[i]n fact I asked her the other day if, if we're engaged how, how can I be tru-, how can be she be totally trusted if she's doing this to her husband?". He said, "[s]o that's the damage that [INDISTINCT] came up".

106. After Mrs Boyce had asked who Laurel was, the appellant said something about "well why did you bring this thing up with Kenneth you know? Would you want me to go through your cell phone and all that?". The appellant said that he attempted to allay Mrs Boyce's suspicions by telling her how dedicated he was to her, and that he had put his practice in New Zealand on hold two years earlier so that they could be together.

107. The appellant said that Mrs Boyce remained suspicious that he was having an affair. He said that he suggested to Mrs Boyce that she would not want him to look through her phone and that she responded by throwing her iPhone off the balcony. The appellant said that should have been the "red flag" because the iPhone was her "lifeline". The appellant said that this happened at around 9.30 pm or 9.45 pm.

108. The appellant said that Mrs Boyce soon calmed down and wanted to kiss and make love. The appellant agreed when the police suggested that that seemed like a big shift: "Yeah well it was and I, it was hard for me to you know, reciprocate completely". She started to hug and kiss the appellant but then changed her mind and said that she was tired and wanted to go to bed. The appellant kept his belongings in a spare bedroom in the apartment, which was not the main bedroom where Mrs Boyce slept. He said that he had slept in the same bed as Mrs Boyce during his stay but that, on the evening of 21 October 2015, she wanted to be alone and, for the first time, asked him to sleep in the spare bedroom. He said that Mrs Boyce went to bed at around 9.30 pm, that he kissed her goodnight, and that he went to bed at around 11.00 pm.

109. The appellant said that he slept with ear plugs (which were seen in the bedroom by a police officer interviewing the appellant) due to Mrs Boyce's snoring and because "she would wake up at 3.00, 5.00 in the morning". He said he woke up at around 5.30 am, which was earlier than usual because the balcony doors were open in the spare room, the road noise was pretty loud and it was bright with the curtains up. He went into the ensuite bathroom of the master bedroom (where his toiletries were located, and which he used while the apartment was being kept tidy to show to prospective buyers), made a coffee (which he said was made for her, although he later said that he "never got to a cup of coffee" but might have put the kettle on), then went to the bedroom to give her a kiss, and that was when he found Mrs Boyce's body.

110. At various points during the police interviews the appellant made comments about the history of his relationship with Mrs Boyce and what his hopes had been for the future. He said Mrs Boyce was "the most beautiful wom[a]n I've ever met in my life, from the day I met her". When she had left him in the United States decades earlier he was "devastated that everything had disappeared. Kind of like today and I took about two months off in medical school and almost didn't graduate ... [i]t was just so devastating to me". He said they were "crazy in love" back in the 1980s and she had kept every letter he had written her all those years. After they reunited in 2013 he "put everything on hold" and put his medical practice aside, because they were "going to do all this back then" but then she had gone into hospital for psychiatric treatment. They got engaged in October or November 2013 and he bought her an engagement ring. She said she had loved him all those years they were apart and he felt the same way. It had "not been easy", but "when she's great, she's great ... she's a stunning person". He then commented, "but the stress was doing something to her. I, I saw things in her ... [t]his visit that I had not seen". He said that until Monday morning earlier that week, Mrs Boyce had seemed "pretty happy" and "we were really positive about the future and everything and she was last night still thinking you know, we'd be getting a house before Christmas in ... New Zealand". He said she was "very keen" on moving to New Zealand. He said "I've been waiting for this to happen for two years and I thought we were finally getting there". The appellant said "I loved her, I was looking forward to, I don't even know where my future is now" and "I hinged everything on her, getting married in a couple of months".

111. Towards the end of the first formal interview, the appellant was asked what he thought had happened to Mrs Boyce. He responded, "I think she got really distressed last night and killed herself", and then said "It was nice work really if you were to [INDISTINCT] you can see there but they were razor sharp ... I've never seen knives so sharp in my life." When asked if he stabbed Mrs Boyce, he said "No I did not stab Maureen ... I love that lady ... With all my heart and I thought we were finally getting close to fulfilling our dreams."

112. Towards the end of the second formal interview, the appellant was informed that detectives had spoken to Mrs Boyce's son who had told them that Mrs Boyce was quite keen for the appellant to go back to New Zealand. The appellant confirmed that was the case, explaining that Mrs Boyce had thought he was making it more difficult for her to sell the apartment. The appellant was then told that Mrs Boyce's son had said that Mrs and Dr Boyce were back together, and that she was selling the apartment in order for them to buy a new place and move in together. The appellant said, "That's news to me ... That's news to me ... Yeah I've, I've been waiting for this to come to fruition for two years and this is shocking that ... This whole thing was a fraud in the first place ... She almost had be [sic] put eighty thousand dollars on a house to hold, which would have been lost in Tauranga just a few weeks ago but I said I didn't want to do it because we didn't know how long it was going to take for her to ... [s]ell her place. She had a lot of secret stuff going on cause I know there was something going on with this other guy too." He said some time later, "Obviously there's a lot I didn't know. This, this thing with Graham just, I, I honestly."

     The prosecution and defence cases

     Mrs Boyce's mental state on 21 October 2015

113. In a trial in which the only two possibilities were that the appellant murdered Mrs Boyce or that Mrs Boyce committed suicide, the prosecution argued that, on 21 October 2015, Mrs Boyce was not in a depressed state and was not having suicidal ideation, still less was there any likelihood of her acting upon any such ideation.

114. The prosecution relied upon the evidence that Mrs Boyce had been to the movies on the afternoon of 21 October 2015 and had been out to dinner that evening. The prosecution also relied on the evidence of Dr Spelman that in his session with Mrs Boyce on 20 October 2015 he considered that Mrs Boyce was not exhibiting any depressive symptoms, and evidence that she was planning for the future such as by telling Ms Russo that she would see Ms Russo at a forthcoming birthday and by asking Dr Boyce to obtain the valuation for the apartment. Dr Spelman said that the pregnancy of Mrs Boyce's daughter was going to be a significant protective factor in reducing her suicidality.

115. On the other hand, Dr Spelman said that Mrs Boyce had not told him about Mrs Boyce's daughter telling Mrs Boyce that she would never meet her grandson or the fact that Mrs Boyce's daughter was not speaking to her. By extension, he would not have known that over the two-week period before Mrs Boyce's death she had sent texts to her daughter but had not received any replies. And there was no suggestion that he was aware of Mrs Boyce's conversation with Ms Neilson only three hours prior to the appointment during which Mrs Boyce told Ms Neilson that she was very depressed and felt suicidal.

464. The apparent proposition underlying Dr Ong's impugned evidence must also be placed in its proper context. His evidence was that he would have considered relevant any prior self‑inflicted injuries indicative of attempted suicide (whether they were fresh or in the more distant past). He accepted that he also would have considered evidence of factors suggesting the deceased's "previous self‑harm". But the deceased had previously only threatened to self‑harm. She had not in fact inflicted self‑harm. Consistently with this, Dr Ong had found no evidence of injury suggesting previous self‑harm or attempted suicide. Moreover, even if the deceased had a history of actual self‑harm (which she did not) and Dr Ong had been aware of that, his point was that this would not be a strong factor, and he would have to consider "all the features" and the "whole picture". The reason he would do so, it must be inferred, results from his expert opinion that the materiality of a history of self‑harm can be gauged only by the other evidence yielded by the autopsy. That is, the very process of assessing the materiality of a history of self‑harm, if any, depends on the application of Dr Ong's expertise as a forensic pathologist.

465. While Dr Ong always looked at the "whole picture", as explained, he did so through his expert perspective. Moreover, in this case, the first factor that led him to consider that the stab wounds were not self‑inflicted was the number of stabs, meaning the number of times the knife had been thrust causing the internal wound tracks. As noted, Dr Ong did not accept that one stab wound with multiple internal tracks was merely "equivocal". He said that the "minutiae of ... the stabbing" had to be considered. He subsequently repeated his refusal to accept the "neutral" status of the multiple stabbings within the one external wound by saying that "multiple stab wounds ... always points towards" the possible involvement of another person, even if they are not, of themselves, a definitive feature. This opinion was plainly based on his expertise as a forensic pathologist.

466. Further, while Dr Ong had found three cases of suicide with one stab wound and multiple internal tracks, none of these involved partial withdrawal and rotation of the knife. Those facts, partial withdrawal and rotation of the knife before replunging the knife in a different direction, would have involved some delay which Dr Ong found "odd". It is plain that, in context, Dr Ong meant that he found this "odd" in respect of a suicide. While he said he had found no reported cases of "a single entry wound, a couple of stabs, the rotation, a couple more stabs" in the literature (and, by this, Dr Ong should be understood to have meant no cases at all in the literature, whether murder or suicide), that does not mean that his evidence – that he found the injuries and how they had been inflicted (multiple stabs causing multiple internal wound tracks with a partial withdrawal and rotation of the knife before reinsertion of the knife) "odd" for a self‑inflicted injury – was not based on his expertise.

467. It is unexceptionable that Dr Ong would bring to bear all his expertise to say that this sequence of events was "odd" for a self‑inflicted injury (and, by necessary implication, not so odd for an injury inflicted by another) where: (a) he had said that multiple stabs, even if inside the same external wound, were always relevant and more indicative of an injury inflicted by another person and, in this case, there were multiple stabs; (b) in other cases of multiple stabs in suicides the stab wounds were fairly superficial (unlike the wounds in this case); (c) the stabbing in this case would have been painful for the deceased; and (d) the partial withdrawal and rotation before reinserting the knife would have involved delay. These are the factors, identification of each of which is itself based on Dr Ong's expertise, which led him to the view that it was more likely these wounds were inflicted by another person, even though he could not definitively exclude self‑infliction. These must also be the factors that he had in mind when he said in his evidence during the pre‑trial hearing that "the logical sense of what has happened" caused him to consider that the injuries were more likely to be inflicted by another person than by the deceased.

468. It is apparent that Dr Ong was not purporting to give evidence as to the deceased's psychological state or, indeed, the psychological state of any person who ends their own life. He was explaining that the evidence of the wounds themselves (the single external wound and the multiple internal wounds showing a partial withdrawal and rotation of the knife), based on his expertise and experience over 25 years, led him to the conclusion that the wounds were more likely to be inflicted by another person than to be self‑inflicted. It is because drawing conclusions from wound patterns involves a process of deductive reasoning based on expertise as a forensic pathologist, and because he had no expertise to opine as to the particular psychology of the deceased at the time of the infliction of the wounds (and did not so opine), that he could not rule out the possibility that the wounds were self‑inflicted.

469. The fact that Dr Ong had not identified such a sequence of events in either a suicide or a homicide caused by stabbing does not mean that his evidence was not based on his expertise and does not mean his evidence lacked a rational foundation. The essence of expertise is the capacity to reason from facts based on specialist training, study, or experience. It is obvious that it is highly unlikely that any case of suicide or homicide reported in the literature will be identical to an actual case which confronts a forensic pathologist. The lack of an identical case of either suicide or homicide does not mean a forensic pathologist such as Dr Ong is incapable of providing an admissible expert opinion. He is entitled to bring to bear all his specialist training, study, or experience to form an opinion without being able to point to an identical or even similar case. It is clear from a fair reading of the transcript of Dr Ong's evidence that the impugned evidence was based on his specialist knowledge and reflected the combined effect of that knowledge brought to bear on multiple facts that he could ascertain only by reason of his specialist expertise: specifically, the single entry wound with no sign of other superficial or smaller hesitation wounds (which are apparent in certain cases of suicide), the lack of any injuries suggestive of a failed attempt at suicide either immediately before the infliction of the fatal wounds or at an earlier time (which are also apparent in certain cases of suicide), together with the multiple internal tracks showing multiple thrusts of the knife into the deceased's abdomen (which are indicative of homicide), as well as the partial withdrawal and rotation of the knife before reinsertion to create three additional internal wound tracks (when multiple stabs are indicative of homicide, and the partial withdrawal, rotation and reinsertion of the knife would have taken time to achieve and involved further pain).

470. The evidence of Dr Ong did not involve merely "putting from the witness box the inferences upon which" the prosecution's case rested[136]. Given his expertise and the underpinning of the impugned evidence, Dr Ong's opinion as to the likelihood of the fatal wounds being inflicted by another person rather than self‑inflicted was not cloaked "with a spurious appearance of authority", and thereby did not involve any risk that "legitimate processes of fact‑finding may be subverted"[137].

     [136]Clark v Ryan (1960) 103 CLR 486 at 492.

     [137]HG v The Queen (1999) 197 CLR 414 at 429 [44].

     Ground two – conclusion

471. For these reasons ground two must be dismissed.

     Order

472. The appeal must be dismissed.

     SCHEDULE

     TEXT MESSAGES, EMAILS AND PHONE CALLS

     1. On 7 July 2013, Mrs Boyce sent a text to her son, Zachary, which said:

     " ... I think I have made a decision to stay with Dad as I have been thinking what would it be like with 2 bipolar people together – not very good. Sorry darling but my emotions are running high. Love you. Mum x".

     2. On 24 July 2013, Mr McAlpine sent Mrs Boyce a message saying, "I'm wondering what happened. Did I offend you? I never had a chance to apologise and explain. I hope you're still talking to, and are still friends with me? X O X". She responded to Mr McAlpine on the same day that "I'm still friends with you Kenneth. This Sat I'm off to Hong Kong as I won the trip for 2 people for one week and I'm taking my son. Talk when I get back."

     3. On 13 November 2013, Mrs Boyce was in New Zealand with the appellant, and she sent a text to her son saying, "NZ is good but I'm a bit sick of [the appellant] sleeping all day and me up watching TV and reading. Classic depression ... I went to Tauranga the other day and walked around on my own which was a good break out of the house. How are you? I hope work is good and hope Dad is well. Love Mum xo". She texted her son later the same day asking if he could change her flight so she could come back to Australia earlier.

     4. Mrs Boyce travelled to New Zealand on 16 February 2015 and did not return until 20 March 2015. On 10 March 2015, Mrs Boyce sent two texts to her daughter, Angelique, saying, "I'm trying to get back to Brisbane Angelique but I'm stuck in South Island New Zealand. I love you and will be back within a week. I will be going to your wedding, Love Mum" and "I should not have come here. I made a mistake. Sorry darling. Love Mum". Her daughter responded, "[y]es you made a massive mistake and have really upset me and Dad who has devoted his whole life to you Mum". Further texts between Mrs Boyce and Angelique on 10 March 2015 included these:

     Mrs Boyce: "Dad and I have been talking by ph and texting Angelique."

     Angelique: "No you haven't spoken on the phone you have only texted. I think you should apologize straight away to him for going!"

     Angelique: "You also haven't bothered to contact me for weeks."

     Mrs Boyce: "I spoke to Dad on the phone today. I haven't contacted you because I was upset with you saying I wasn't invited to your wedding. I love you and made a big mistake. Sorry, darling. Love, Mum."

     Angelique: "I accept your apology but please stop lying to me."

     Angelique: "It can't continue or you will loose [sic] your daughter."

     Mrs Boyce: "Ok darling. How are you and Andrew getting on with all the stress of a wedding. Dad said you two have been fighting. You can make the wedding at a later date if you haven't sent out invitations. Love Mum".

     5. On 9 April 2015, Mrs Boyce sent a text to Mr McAlpine:

     "Kenneth I'm in shock. What are you disappointed in? I just called you but got message bank. Can you text me with a good time to call you please. I really need to talk to you. I want to tell you what's happened to me. I'm on suicide watch because of my news. I can't bear the thought of us not being friends. I want to tell you with my voice not by text. Please text me Kenneth. I need so much to hear from you. Maureen xxoo".

     6. On 18 May 2015, Mr McAlpine sent two texts to Mrs Boyce:

     "I truly think we would do each other a world of good to [catch] up and spend casual time together, realising we are both okay. If we want to be ourselves. I miss you heaps x O x".

     "I truly think we would do each other a world of good to catch up and spend casual time together, realising we are both okay ... If we want to be ourselves. I miss you heaps x O x Don't be shy. Remember how good and easy it is for us."

     7. Mrs Boyce sent a text back to Mr McAlpine the same day saying:

     "Glad you are enjoying the dusk. Guess what, my daughter Angelique gets married in 2 weeks time on the 30th May. I'm going to Sydney with her tomorrow for her to have final fitting for her wedding dress. The designer is from Israel. The dress is go[r]geous. It is made of lace and is backless with a long train. Nice to hear from you but timing is not good. Luv ya Maureen".

     8.        Mr McAlpine responded a few minutes later:

     "I remember. It all sounds exquisite. I will wait and wait to see you. But don't torture me."

     9.The two continued texting on 18 May 2015, including these messages:

     Mr McAlpine: "Absolutely fab. Enjoy and remember. Love to you x x".

     Mr McAlpine: "But i get the feeling i will never see you again. I feel i wont be important enough. That's wrong, but all I have to go on."

     Mrs Boyce: "Kenneth don't be silly. I just have to get through a wedding ... See you soon. Luv ya Maureen".

     10. On 7 June 2015, Mrs Boyce sent a text to the appellant:

     "I can't believe that you have said to me I've forgotten how to love and am too much into myself! I have worn a blood pressure monitor for 24 hrs and I have high blood pressure and have to take half a tablet morn and night! I wanted to commit suicide yesterday by going out in a cruise boat to the reef and jump over the back of the boat. We can talk anytime up until 10pm my time."

     11. The appellant sent a text back later that night:

     "Mimi, what's harder. The effort it takes to get here or to continue on the brink of suicide and flirting w it daily? The autumn colors persist here tho you will want warm clothes. You can stay for a while in quiet loving sanctuary (get 1 way tic). If not then i'm coming there or meet you in Brisbane this week. You would insist on the same were it reversed. Don't decide now but sleep on it & let subconscious process it and I'll call you in morn. You know I'm right. Also no rush to sell, July is NOT best month ... A place like yours will sell in 1-5 days. But first things first YOU then US. Talk in am. Relax and rest well."

     12. On 22 June 2015, the appellant sent an email to Mrs Boyce with information about divorce in Australia which ended:

     "I hope this is helpful as a guide and makes the process less stressful for you. Your everloving and eternal soulmate".

     13. The appellant sent another email later the same day saying she should separate her apartment from the property of her husband before its sale and he did not think it "wise to make ANY assumptions about how [Mr Boyce] will proceed once divorce process in[i]tiates".

     14. On 27 June 2015, Mr McAlpine and Mrs Boyce were in text communication, their texts saying:

     Mr McAlpine: "How are you?"

     Mrs Boyce: "Still depressed and I'm not in Brisbane. I send my love to you, Maureen".

     Mr McAlpine: "I will be in Cairns from the 13th. If you don't wish to see me, I give up."

     15. On 4 July 2015, the appellant sent an email to Mrs Boyce about an advertisement to see the Imperial Russian Ballet perform Swan Lake in Tauranga, New Zealand, in November 2015 saying, "CAN YOU COMMIT TO BEING HERE? IF SO WILL GET SUPER TIX!!"

     16. On 9 July 2015, Mrs Boyce sent a text to Mr McAlpine saying, "Hi Kenneth, I'm still in Sydney not Cairns having treatment for my depression. I guess you will now give up on seeing me again. I don't blame you as I'm really sick. Sorry! I still send love to you, Maureen".

     17. On 14 July 2015, the appellant sent Mrs Boyce an email saying, "[t]hink about being here in NZ on 23 Aug and 27 Aug for 2 great concerts in Auckland. and Sept 5 & 6. perhaps go back after this?? We will [talk] BEFORE committing/planning."

     18. On 16 July 2015, the appellant sent Mrs Boyce an email about "[g]obsmacking homes" he had been to see in New Zealand. He sent another email about homes on 19 July 2015, with a further email on 23 July 2015 under the heading, "THIS IS THE PERFECT CLASSY HOUSE FOR US".

     19. On 9 August 2015, the appellant sent Mrs Boyce an email with flight information between Auckland and Brisbane ending with "One Way grab". He sent her more flight information the next day, 10 August 2015. On 13 August 2015, he sent her an email about the Tauranga festival saying, "TO LOOK FORWARD TO: HOPEFULLY TGA WILL BE YOUR HOME BY THEN!!!!!!!!!!!!!!!!"

     20. Between 20 August and 1 September 2015 there were a series of texts Mrs Boyce sent her daughter including these:

     Mrs Boyce: "Angelique, Zachary is wanting you to call him with the sex of your baby. Let him guess I didn't tell him."

     Mrs Boyce: "Angelique hope you are feeling well and not too tired. You will have to book your baby into private school - Boys Grammar or Churchie are the best. Love Mum".

     Mrs Boyce: "Hi darling we are at Sheraton Mirage at Port Douglas lying around the lagoon!!! It's perfect day with sunshine. Zachary is working at North West Hospital today and he just did a Caesarian [sic] which was a boy. How exciting!! Love Mum".

     Mrs Boyce: "Hi Angelique, Macleay Towers ... is open for inspection at 2.15pm till 3pm today. Do you think you and Andrew could go for an inspection and see what real estate man says to you. Don't tell you are related to us. Thanks love Mum".

     Mrs Boyce: " ... Our sub penthouse is open for inspection till 3pm today. Please look at it. Love Mum".

     21. On 25 August 2015, Mrs Boyce sent a text to her son saying, "I'm great. I'm out of my depression totally feel good. I get up early each morning now at 8am which is so wonderful. Happy studying love Mum".

     22. On 1 September 2015, she sent a text to the appellant saying, "[c]an't wait to see you babe and make love!!"

     23. On 3 September 2015, Mrs Boyce's daughter said she would come over to see her on the weekend.

     24. On 3 September 2015, Mrs Boyce and the appellant exchanged a series of texts including these:

     Appellant: "how is my darling on this blesse'd day? Love and miss you – sure would like to kiss you!"

     Mrs Boyce: "I'm great darling how are you? I also would love to kiss you too, not long now 1 week. Man from New Guinea loves my place and said his wife is coming to look at it in 2 weeks time."

     Appellant: "Hi darl, what is your Brisbane mortgage currently? Tt".

     Mrs Boyce: "A couple of hundred thousand dollars. Insignificant! Why??? M".

     Appellant: "Just thinking of our future options! T xox".

     Mrs Boyce: "What about your options?"

     Appellant: "OUR options".

     Mrs Boyce: "What about my options? M Graham has a life insurance valued at $5 million and I'm the sole beneficent."

     Mrs Boyce: "What exactly are you thinking about for OUR future options?"

     Appellant: "We have much to discuss".

     Mrs Boyce: "Call me now if you can. What exactly do you want to discuss?"

     Mrs Boyce: "I want to talk to you now or else I'm cancelling my trip to NZ".

     25. The appellant said he would call Mrs Boyce after a movie. Mrs Boyce then contacted Mr McAlpine who sent her a text on 3 September 2015 saying, "[t]hats [sic] wonderful news. So glad to hear it ... would love to catch up in person before you fly away again." Mrs Boyce responded, "[y]es. Love to. M XOX" to which she received a text " ... is the CORRECT ANSWER! All you need to do is name your time and day to receive your prize". She responded, "Ha ha!! Can't wait to receive my prize. One day next week Mon or Tues sounds good. M xx".

     26. A series of texts between Mrs Boyce and her daughter followed arranging her daughter and her son‑in‑law's visit to the apartment.

     27. On 4 and 6 September 2015, the appellant and Mrs Boyce exchanged sexually intimate text messages.

     28. On 7 September 2015, Mr McAlpine sent Mrs Boyce a text saying, "[h]ello there. About what time would you like me to drop over? It would be nice to see the sunset. X". She responded that she could not see him as she had been invited by a girlfriend to the Gold Coast for a few days and then would fly to New Zealand, ending with "would still love to catch up when I return. I'll call you after I come back from NZ. I'm feeling great and hope you are too. Take care luv ya Maureen". Mr McAlpine responded, "I spent all day yesterday running around and arranging things so I would have today free. Can't say I'm not disappointed when all you had to do was call. Can't say I'm surprised either. Bye".

     29. By 11 September 2015, Mrs Boyce's son and daughter had found out she was going to New Zealand. Her son sent texts saying, "Dad's very upset that you would spend his money to go over there and now he can't pay his tax bill" and "[y]ou only phone dad or hang around him when you need something: when you're depressed or need money. It's terrible." Her daughter sent a text saying, "[y]ou have ruined our family Maureen. I want nothing to do with you ever again. Stay away from Dad, Andrew, Me and my baby boy. You will never ever meet your only grandson!!!!! You have caused this. You slut!"

     30. Mrs Boyce travelled to New Zealand between 11 and 25 September 2015.

     31. On 23 and 24 September 2015, while Mrs Boyce was in New Zealand, Mr and Mrs Boyce exchanged texts, in one of which Mr Boyce said, "[b]ut you would be best to stay permanently in n.z.", and Mrs Boyce said, "[s]top playing games!!! I'm coming back to Brisbane", "I'm finished with him and I can meditate now!", and "[w]hat have you been saying to Angelique? She sent me the nastiest text message."

     32. On her flight back to Australia on 25 September 2015, Mrs Boyce sent a text to the appellant saying, "[j]ust got upgraded to first class. I'm drinking French Champayne [sic] !!!" She sent another text to the appellant later that day saying, "[m]iss you already darling. Just got home". The next day, 26 September 2015, the appellant sent a text to Mrs Boyce saying, "I LO[V]E YOU DARLING !!!!!!!!!" Mrs Boyce also received a text from Mr McAlpine later that day saying, "[j]ust in case you don't recognise me, I'll be the tall fellow with the short hair that can't keep his hands off you ;-) X" to which she responded, "[h]a ha! Just in case you don't recognise me I've had my curly hair straightened!!! Luv ya Maureen". Still on 26 September 2015, the appellant sent a text to Mrs Boyce saying, "[d]arling I have re-emailed u the divorce info; Tt", to which Mrs Boyce responded, "going to Sarina's party. I feel so horny and want us to make love. Do you think you could call me now? Mt". Mrs Boyce then sent a text to Mr McAlpine saying, "[w]hat time are you coming Kenneth?" and he responded that he was still on the way as the traffic was "mad". Later in the evening of 26 September 2015, the appellant sent Mrs Boyce a text saying, "everyday I fallin [sic] love with you all over again!"

     33. Texts between the appellant and Mrs Boyce continued on 27 and 28 September 2015 including these:

     Appellant: "I miss you terribly darling! Tt".

     Mrs Boyce: "I always wanted to live in Brentwood LA but now I love NZ and you! Mt Make love to me now! So turned on."

     Appellant: "I'm sad missing you terribly. Tt".

     34. On 28 September 2015, Mrs Boyce texted her husband saying, "I'm now finished with you so good luck!!!" and "Deanne said she has a buyer for Macleay! I will go to Noël Barbi alright for our divorce!!! You are a horrible assehole [sic] to me and have been for 39yrs. I'm sick of dancing around your moods like this morning when I called you. You couldn't talk because you said you had just got up", to which he responded, "I am so sorry for all i have put you through". The next day, Mr Boyce sent his wife a text saying, "[w]ould you go see dr kennedy who is looking after marks patients". In between texts with Mr McAlpine about the moon, a sunset, and her lost keys, Mrs Boyce sent a sexually intimate text to the appellant, as well as two texts to her husband saying, "I knew you were a nasty SOB just like your mother going around telling people I have mental illness ... but I didn't think you would stoop this low and dirty. Putting on Facebook when I went to NZ crash slut was disgusting. I now want a divorce and I'm serious!!!" and "I need to ruin your reputation in Brisbane ... I will start with Andrew Pennisi!"

     35. Between 30 September and 5 October 2015, there was a series of texts between the appellant and Mrs Boyce interrupted by one text from Mrs Boyce to her daughter on 3 October 2015 saying, "[t]o call your mother a slut is so disrespectful and horrible. Remember I gave birth to you and have done so much for you. I repeat I am not a slut I'm your mother. When you apologise to me I may talk to you again." The texts between the appellant and Mrs Boyce included these:

     Mrs Boyce: "Why don't you come visit me for a couple of weeks on your birthday. I can pick you up at airport. Love Maureen".

     Mrs Boyce: "It's your birthday tomorrow!! What's wrong darling? I haven't heard from you. Just got home from hairdressers and real estate man is coming here at 3.30pm for meeting with me. Mt".

     Appellant: "been down since you left, bummer. Tt".

     Mrs Boyce: "I'm sorry to hear that. Read Jesus Lives. It so fantastic and I read it each day. I just love it. Why don't you get on a plane and visit me in Brisbane. Love Maureen".

     Mrs Boyce: "STOP SMOKING!!! It causes depression. You won't be in the way here so get on a plane tomorrow and come here only 3hr flight. You can't smoke here so come on over. Love you. Mt".

     Mrs Boyce: "Come to Brisbane darling. It's time we let our adult offspring take care of their own lives. It's time for us. M".

     Mrs Boyce: "Why don't you call me. Sorry I missed your call today. Mt".

     Mrs Boyce: "Call me darling. I called you at 11am this morning for your birthday. Mt".

     Mrs Boyce: "Don't worry about your son. He'll be ok. I think you were about 26 when I got pregnant with Zac! Look what happened there. Maybe you were a year older I can't remember. It's time to look after yourself darling. Mt".

     Mrs Boyce: "To the love of my life ... happy birthday darling, may you have a wonderful day today and always all my love from Maureen XXXOO".

     Appellant: "I am feeling terrible darling, can you come here? Tt".

     Mrs Boyce: "I can't come there darling. You come here just jump on a plane and it's only 3hrs flight. I'll pick you up at the airport. My place is open for inspection now".

     Mrs Boyce: "Why don't you pack a few things and get on a plane and come here only 3 hrs. I'll pick you up from the airport. Mt".

     Mrs Boyce: "Book a flight this afternoon and come visit me this afternoon!!"

     Appellant: "I got my ticket for Brisbane TUES from Tga 115 arr 420."

     Mrs Boyce: "Wow! [sexually intimate details]".

     Appellant: "yes darling; aiming to be there Tues. Need you. Tt"

     Mrs Boyce: "I forgot to ask you on the phone. Can you bring me 2 bottles of Limoncello from duty free Auckland ... Thanks darling. Look forward to seeing you. Mt".

     Mrs Boyce: "Darling [sexually intimate details]".

     Appellant: "Yes I thought you took it home; you will find; I need you and your love; my soul in turmoil. T."

     Appellant: "gnite my lover Tt".

     36. The appellant travelled from New Zealand to Brisbane on 6 October 2015.

     37. By 8 October 2015, Mr McAlpine and Mrs Boyce were exchanging texts with Mrs Boyce saying on 11 October 2015, "I've got friends from New Zealand staying with me for about 1 more week. We must then catch up. Luv ya Maureen" to which he responded, "[y]es lets. Mwah x".

     38. Between 11 and 14 October 2015, Mrs Boyce and her son exchanged texts. He said, "[d]isgusting you would have someone there when dad is sick and working" to which she responded, "[the appellant] arrived yesterday and is severely depressed" and "[d]on't tell Dad. No need to upset him, I hope [the appellant] doesn't stay long as I know about depression. Love Mum". Mother and son agreed they would go out to dinner with him saying, on 14 October 2015, "[w]e can do dinner fri night before the show. I don't want to see [the appellant] though".

     39. On 15 October 2015, Mrs Boyce sent a text to Mr McAlpine saying:

     "My kiwi friends are still staying with me so I can't see you for another week. They won't leave. I think I will have to be rude and ask them to leave next week. I've had enough. Hope you're well. Luv ya Maureen".

     40. On 16 October 2015, Mrs Boyce's son sent her a text saying, "[w]e can get dinner before the show at 730 tonight. Just you and me. I will meet you in my car at front of our building at 6pm". Mother and son continued to exchange texts about his sore throat on 16 and 17 October 2015.

     41. From 18 to 21 October 2015, Mrs Boyce made numerous attempts to contact her husband. One text she sent him at 5.28 am on 19 October 2015 said, "I feel all depressed again. Up at 3am today." Mrs Boyce sent him another text at 7.14 am on 21 October 2015 saying, "[c]an u call me ASAP". She then received a text from her friend Sarina Russo on 21 October 2015 about the sale of her apartment saying, "[a]wesome ad – powerful language – today it's 'sold'!!!" Mrs Boyce responded saying, "[t]hanks Sarina. I wrote the ad and Colin offered me a job in Real Estate. I haven't seen the Fin yet. Love Maureen". Mrs Boyce then again attempted to contact her husband between 7.34 am and 7.51 am on 21 October 2015 including sending a text at 7.34 am repeating "[c]an u call me ASAP". Mr Boyce made several attempts to contact his wife from 9.06 am onwards on 21 October 2015. Mrs Boyce also called Mr McAlpine at 10.54 am on 21 October 2015. On 21 October 2015, she also called Sarina Russo twice who then sent a text at 9.04 pm that evening saying, "[s]tay positive! Luv Sarina". That evening there were also calls and missed calls between Mrs Boyce and her husband at 7.04 pm, 7.40 pm, 8 pm, and 8.03 pm. Mr McAlpine and Mr Boyce tried to contact Mrs Boyce the following day, by which time she was dead.