New trial ordered

Yukon Court of Appeal orders new sexual assault trial after Crown breached a sexual history ruling mid-trial

When the Crown opened the door to evidence the trial judge had excluded, the judge had to revisit her ruling on her own initiative. A jury instruction and a yes or no question in re-examination did not restore a fair trial.

R. v. Weatherston, 2026 YKCA 5

6 min read

Court: Court of Appeal of Yukon
Decided: Mar 20, 2026
Conviction to this result: 2 years
Sentence: Not stated in the decision

Appeal allowed, conviction quashed, new trial ordered The conviction was set aside, but the charge can be tried again. The presumption of innocence applies.

What happened

The appellant and the complainant had been together about four years but did not live together. In December 2020 she told him she had been with another man. Their accounts of what followed differed sharply. She said he became angry and threatened the other man, and that she feared him because of stories he had told about his past. A few nights later, at his home, she said he told her to undress and go to the bedroom, that she froze and complied out of fear, and that sexual activity took place without her consent. She agreed there had been no earlier violence. She said the relationship continued for about eight months afterwards because she did not want to admit to herself that she had been sexually assaulted. The appellant denied the assault and said he believed the activity was consensual. He said the disclosure made him sad, not angry, and that the relationship did not end then. In direct examination he said she agreed to go to the bedroom. In cross-examination he changed that and said she never verbally consented, and repeated this in re-examination. The judge found no air of reality to a defence of honest but mistaken belief in communicated consent, so it was not left to the jury. Before trial the Crown was permitted to lead evidence of the disclosure and the alleged angry reaction. The appellant applied under s. 276 of the Criminal Code to explain that the couple had earlier agreed to an open relationship, to show why he was not angry. His affidavit said they had returned to monogamy by autumn 2020. The judge refused the application as irrelevant. A jury convicted him in September 2024.

Procedural history

Undated
Charged with one count of sexual assault under s. 271 of the Criminal Code (Whitehorse Docket 22-01513)Supreme Court of Yukon
Apr 23, 2024
Appellant swore an affidavit in support of his s. 276 application to lead evidence of an earlier open relationshipSupreme Court of Yukon
2024
Pre-trial ruling: Crown's Seaboyer application granted, appellant's s. 276 application dismissed as irrelevantSupreme Court of Yukon
Sep 18, 2024
Appellant testified; Crown cross-examination raised monogamy and his s. 276 affidavit before the jury; defence objected; judge adjournedSupreme Court of Yukon
Sep 2024
Judge accepted a joint proposal: mid-trial instruction to disregard the non-monogamy evidence, and a limited re-examination; no air of reality ruling on mistaken belief defenceSupreme Court of Yukon
Sep 20, 2024
Jury found the appellant guilty of sexual assault; conviction enteredSupreme Court of Yukon
Jan 15, 2025
Trial judge rescinded the s. 486.4 publication ban on a consent applicationSupreme Court of Yukon
Nov 21, 2025
Conviction appeal heard in WhitehorseCourt of Appeal of Yukon
Mar 20, 2026
Appeal allowed on the second ground, conviction quashed, new trial orderedCourt of Appeal of Yukon

The offence and its elements

Sexual assault

Criminal Code, R.S.C. 1985, c. C-46, s. 271

What the prosecution had to prove:

The accused intentionally applied force to the complainant (touching)not addressedGeneral law: check the current text
The touching was of a sexual nature, viewed objectivelynot addressedGeneral law: check the current text
The complainant did not consent to the sexual activitydisputedFrom the reasons
The accused knew the complainant was not consenting, or was reckless or wilfully blind to that, with no honest but mistaken belief in communicated consent based on reasonable stepsdisputedFrom the reasons

The questions on appeal

Did the trial judge err in dismissing the appellant's s. 276 application to lead evidence of the earlier open relationship?: Not decided. The court called the dismissal a very close call, said it was open to the judge to admit some of the evidence given the Crown's theory of fear, and could not follow the judge's second reason. But it did not need to find a reviewable error because the second ground alone decided the appeal.
Did the judge fail to manage the trial properly after the Crown breached the s. 276 ruling in cross-examination, so that the appellant could not make full answer and defence?: Yes. The Crown's questions about monogamy and the appellant's affidavit were a material change in circumstances. The judge should have revisited the s. 276 ruling on her own initiative. The mid-trial instruction and the yes or no re-examination did not restore fairness, and the Crown's closing and the jury charge made things worse.
Could the conviction be saved by the curative proviso in s. 686(1)(b)(iii)?: No. The errors were not harmless and the evidence of guilt was not so overwhelming that a conviction was inevitable.
Did the judge err on the disreputable conduct evidence or in finding no air of reality to the honest but mistaken belief defence?: Not decided. These grounds were unnecessary given the result on the second ground.

The law the court applied

Standard of review for trial management decisions

Evidentiary errors are reviewed for correctness. Trial management decisions attract deference unless there is an error in principle or an unreasonable exercise of discretion, viewed in the context of the trial as a whole.

R. v. Samaniego, 2022 SCC 9

Admissibility of sexual history evidence under s. 276

The accused must show the evidence is not for twin myth reasoning, is relevant to an issue at trial, concerns specific instances, and has significant probative value not substantially outweighed by prejudice. It must respond to a specific issue that cannot be resolved without it.

R. v. Darrach, 2000 SCC 46; R. v. Goldfinch, 2019 SCC 38; R. v. T.W.W., 2024 SCC 19; R. v. Kinamore, 2025 SCC 19

Revisiting a sexual history ruling mid-trial

A judge may, on their own initiative or at a party's request, revisit an admissibility ruling where there is a material change in circumstances, such as evidence evolving during trial.

R. v. Kinamore, 2025 SCC 19 at para. 57

Mistrial threshold

A mistrial is a discretionary remedy for the clearest of cases where there is a real danger that trial fairness has been compromised and cannot otherwise be repaired. A mid-trial instruction can sometimes be enough.

R. v. Barra, 2021 ONCA 568; R. v. Dueck, 2011 SKCA 45; R. v. Chiasson, 2009 ONCA 789; R. v. Gill, 2017 BCCA 67

Judge's responsibility despite lack of objection

A party's failure to object, or consent to an instruction, is secondary to the judge's overall responsibility for trial fairness and does not decide whether the charge was proper.

R. v. Khill, 2021 SCC 37; R. v. Barton, 2019 SCC 33; R. v. Pirko, 2023 BCCA 120

Curative proviso

The Crown must show the error was so minor it could not have affected the verdict, or that the evidence was so overwhelming that conviction was inevitable. The standard is high.

Criminal Code s. 686(1)(b)(iii); R. v. Hussein, 2026 SCC 2

What the court decided

A unanimous three judge panel of the Court of Appeal of Yukon, in reasons by Justice Abrioux, allowed the appeal on the second ground, quashed the sexual assault conviction and ordered a new trial. The Crown admitted that its cross-examination about monogamy, which referred to previous litigation and to the appellant's sworn affidavit, breached the s. 276 ruling. That breach made the nature of the relationship relevant to the central question of whether the appellant was sad or angry, and was a material change in circumstances. The judge should have reconsidered the s. 276 ruling on her own initiative, and could have crafted a remedy short of a mistrial. Instead, a mid-trial instruction that did not address the references to previous litigation or the affidavit, and a re-examination that let the appellant say only that he had a reason for not being angry without saying what it was, left the jury to speculate and unable to assess his credibility. The Crown's closing, which accused him of lying about his reaction while knowing he was barred from explaining, and a charge that asked the jury to weigh the impact of the disclosure on a relationship whose nature they did not know, made the unfairness worse. The curative proviso did not apply. This is a published decision.

What happens next: A new trial has been ordered in the Supreme Court of Yukon. The appellant is presumed innocent at that trial. The packet does not give a date.

Analysis

This is our commentary, separate from the court’s reasons.

Why the case turned on a question that was never answered

The court described the appellant's alleged anger as the central pillar of the Crown's theory, not as the whole of it. On that theory, his reaction to the disclosure contributed to the complainant's fear, and that fear was said to explain why she went along with what he demanded. The Crown also argued that the disclosure had in effect ended the relationship, so that the appellant would have known she was not there for sex. Each of those points was contested. The appellant said he was sad rather than angry, and that the relationship continued for months. The jury still had to decide consent and the appellant's knowledge on all of the evidence. But anger was the point on which his credibility was most exposed, and the one fact that might have supported his account of his reaction was shut out by the s. 276 ruling. That was tolerable, if barely, while the Crown left the subject alone. The moment Crown counsel told the jury there had been previous litigation, referred twice to an affidavit the appellant had sworn, and suggested his own sworn words contradicted him, the jury learned there was a hidden explanation and was then told to ignore it. The court saw that the harm was not the word monogamy itself. It was the impression of a man who had something to say and would not say it.

The remedy that pleased everyone and protected no one

The most useful part of this judgment is its treatment of the joint proposal. Both counsel agreed on the fix, the judge thanked them for it, and no one sought a mistrial. The court did not treat any of that as irrelevant. It acknowledged the agreement and the absence of objections, but held that they were secondary to the judge's overall responsibility to keep the trial fair. What troubled the court was the mismatch between the problem the judge had herself identified and the remedy she adopted. She had said the horse was out of the barn and that the appellant looked not credible on the question of anger, yet the joint proposal answered only her concern about the jury hearing of non-monogamy, and she did not say how it met the credibility concern. The court did not announce a general duty to give reasons for accepting an agreed remedy. Its point was narrower: in this trial, the remedy addressed the wrong harm. The judgment also shows that a yes or no question in re-examination can be worse than silence, because it confirms a secret without disclosing it. The court's sketch of a workable alternative, a renewed s. 276 inquiry, testimony on the nature of the relationship, carefully limited recall of the complainant and a proper instruction, is a practical template for trial judges facing an inadvertent breach.

What it adds to the law on sexual history evidence

The decision applies Kinamore's direction that a judge may revisit a s. 276 ruling on their own initiative when circumstances materially change, and holds that a Crown breach of the ruling is such a change however defence counsel labels it. It also stresses, following Avila, that the gatekeeping duty applies no matter which side leads the evidence. At the same time the court kept the complainant's interests in view. It did not hold that the open relationship evidence should have come in, only that the fairness problem created by the Crown had to be confronted rather than papered over. The court assessed the instruction, the re-examination, the Crown's closing and the charge together, as a cumulative picture, and found the trial unfair on that basis. The first ground was left open, with a candid note that it was a very close call.

If this feels close to home

A breach of an evidentiary ruling by the other side can change what is relevant. Under Kinamore a judge may revisit a s. 276 ruling mid-trial when circumstances materially change, and a request to lead previously excluded evidence should be treated as a request to reopen that ruling.
Agreeing to a remedy at trial does not bar an appeal on fairness. The judge keeps overall responsibility for a fair trial, and the court treated counsel's agreement and failures to object as secondary to that duty. Still, the appellant himself told the appeal court it was unfortunate that his trial counsel did not seek a mistrial, so making the request on the record avoids the point being raised against an accused.
In this case the instruction to disregard covered only the non-monogamy evidence and said nothing about the Crown's references to earlier litigation or the appellant's sworn affidavit. The court weighed that gap together with the limited re-examination, the Crown's closing and the charge. A partial instruction can draw attention to a gap rather than close it, but whether it does depends on the trial as a whole.
The curative proviso is hard for the Crown to satisfy where the error touches credibility on the central issue in a case that turned on two conflicting accounts.
A new trial is not an acquittal. The appellant remains presumed innocent. The court decided only the second ground and left the first ground open; it did not say how any future proceedings should unfold.

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What went wrong

Police or Crown misconduct Trial judge error

How this was checked

Written by Claude Fable 5.1 (Anthropic AI) from the source below, then independently audited against it by GPT-6-Astra (OpenAI AI) on Nov 1, 2026. Every citation here was confirmed by software to appear in the decision or an official text. No lawyer has reviewed this brief. Our standards

New trial orderedNov 6, 2026

Jury wrongly told consent must be communicated; Ontario Court of Appeal orders new sexual assault trial

A judge told jurors there was no consent in law unless the complainant communicated it by words or conduct. That is not the law for the act of sexual assault. Combined with a Crown closing that said the accused had every reason to lie, the conviction could not stand.

R. v. C.L., 2026 ONCA 791 · Ontario · Trial judge error, Police or Crown misconduct

Appeal dismissedSep 3, 2026

Defence held to the stated purpose of its section 275 application: rape appeal refused with no miscarriage of justice

Scotland's appeal court held that excluding a message and alleged jokes caused no miscarriage of justice. The defence had sought that evidence only to explain a remark the appellant made in his own call to the emergency services, and his own trial evidence gave a different explanation for it.

Nairn Sharp v His Majesty's Advocate, [2026] HCJAC 41 · Scotland · Trial judge error

Appeal dismissedJul 15, 2026

Appeal fails: paediatrician's evidence caused no miscarriage of justice and the judge's medical summary was balanced

The High Court of Justiciary refused an appeal against a conviction for attempting to murder a baby. It held that the expert's evidence did not go beyond her expertise in any way that caused a miscarriage of justice, that the prosecutor was entitled to rely on the appellant's delayed and shifting accounts, and that the trial judge's review of complex medical evidence was fair.

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Citations

R. v. Weatherston, 2026 YKCA 5 The decision briefed
R. v. Seaboyer, [1991] 2 S.C.R. 577, 1991 CanII 76Crown application to lead sexual history evidence; right to full answer and defence
R. v. Kinamore, 2025 SCC 19Framework for Crown sexual history applications and revisiting rulings on material change
R. v. Darrach, 2000 SCC 46Burden on the accused under s. 276
R. v. Goldfinch, 2019 SCC 38Evidence must be integral to full answer and defence
R. v. T.W.W., 2024 SCC 19Evidence must respond to a specific issue at trial
R. v. H.P., 2022 ONCA 419Accused may be cross-examined on s. 276 affidavit
R. v. Samaniego, 2022 SCC 9Standard of review for trial management
R. v. Chiasson, 2009 ONCA 789Mistrial and mid-trial instruction
R. v. Barra, 2021 ONCA 568Real danger to trial fairness test
R. v. Dueck, 2011 SKCA 45Mistrial only in clearest of cases
R. v. J.J., 2022 SCC 28Trial fairness and full answer and defence
R. v. Gill, 2017 BCCA 67Mid-trial instruction as remedy
R. v. Araya, 2015 SCC 11Jury charge assessed as a whole
R. v. Avila, 2025 BCCA 5Judge's gatekeeping duty over Crown-led sexual history evidence
R. v. Hoffman, 2024 BCCA 98Presumption juries follow instructions
R. v. Whitmore, 2021 BCCA 302Unclear instructions may warrant new trial
R. v. Khill, 2021 SCC 37Judge's responsibility regardless of objection
R. v. Barton, 2019 SCC 33Consent to instruction not determinative
R. v. Pirko, 2023 BCCA 120Consent to instruction not determinative
R. v. White, 2011 SCC 13Not every instruction error requires new trial
R. v. Hussein, 2026 SCC 2Curative proviso framework
Criminal Code, R.S.C. 1985, c. C-46Sections 271, 276, 486.4 and 686(1)(b)(iii)

Sources

R. v. Weatherston, 2026 YKCA 5

This brief is general information about one case. It is not legal advice, and it may not reflect later developments. Read the full reasons and speak to a lawyer about your own situation.