WARNING: This article contains details of sexual assault.

A new trial has been ordered in the case of Leslie Iain Weatherston, who was convicted of sexual assault against his former partner in September 2024.

Police arrested and charged the Dawson City, Yukon, resident in August 2022 after his former partner reported that he had sexually assaulted her two years earlier.

Weatherston was sentenced to 18 months in jail following a jury trial in 2024.

A Yukon Court of Appeal judge now says that trial was unfair.

In his decision published last Friday, Justice Patrice Abrioux said the trial judge, Yukon Supreme Court Justice Karen Wenckebach, erred several times — including in trial management.

Justice Abrioux, back by two other judges, said the errors were significant enough that the verdict might have been different if they hadn’t happened.

“The appellant was prevented from exercising his right to make full answer and defence, which in turn engendered a miscarriage of justice,” Abrioux wrote.

Weatherston’s appeal lawyer, Jennifer Budgell, said this is a crucial part of the Court of Appeal’s findings.

“In my view, a mistrial would have been the only appropriate remedy in this case,” she told CBC News.

Budgell also said the Court of Appeal’s decision is not surprising.

“We knew from the initial review of the case that a number of things had gone wrong with this trial,” she said.

Weatherston filed a notice to the Yukon Court of Appeal in February 2025, a month after being sentenced. In his appeal, he also claimed the judge made a number of errors during his trial, including dismissing his application to admit certain evidence.

He also asked to have new trial in front of a jury again.

‘Cornered’ during cross-examination

During a pre-trial conference, Wenckebach ruled against Weatherston’s cross-application request to present some evidence about the nature of the relationship with his former partner.

In his verdict, Justice Abrioux said that decision prevented a fair debate around some aspects of the relationship.

During 2024 trial, the jury heard that at the time of the alleged assault, Weatherston and his former partner had already been in a relationship for several years.

His former partner testified that a few days before the incident, she had told Weatherston that she had been with someone else. She said she started being afraid of Weatherston after he reacted badly to the confession.

The Crown, however, asked Weatherston closed-ended questions about his reaction and the nature of the relationship.

Justice Abrioux ruled that the Crown “effectively cornered” Weatherston during cross-examination.

Without being allowed to present evidence to back his answers, Justice Abrioux said Weatherston didn’t appear to be credible and was unconvincing.

“The complainant was permitted to testify about the appellant’s reaction to her disclosure that she had been with another man,” he wrote.

“The appellant, however, was left in a position where he could do little more than issue a bare denial, without the ability to provide any meaningful explanation in response.”

Budgell said the jury didn’t have an opportunity to hear Weatherston’s explanation.

In order for the retrial to be fair, Budgell said the evidence will have to be admitted.

The Court of Appeal’s written decision also notes the Crown admitted to improper questioning about the nature of the relationship.

Justice Abrioux said even after that admission, the trial judge erred in failing to restore the fairness of trial. He said Justice Wenckebach could have declared a mistrial or reopened an application for evidence.

He also said the judge erred in instructing the jury to simply ignore the Crown’s question and Weatherston’s answer about the nature of the relationship.

He said instructing the jury to consider the impact of the relationship between the parties, without having evidence as to the nature of the relationship, made the trial unfair.

“The instructions were, respectfully, flawed,” Abrioux’s decision reads.

A date has yet to be set for the new trial.