The appellant was convicted of second degree murder and unlawful possession of a firearm following a jury trial in which the Crown called a former co-accused as a witness.
The trial judge issued a Vetrovec warning cautioning the jury about the witness's credibility, despite the witness giving exculpatory testimony.
The majority of the Court of Appeal found that the Vetrovec warning was given in error but applied the curative proviso, holding the error harmless.
The dissenting judge found application of the curative proviso inappropriate.
The Supreme Court unanimously allowed the appeal, adopting the reasoning of the dissenting judge, and ordered a new trial.