R v Cowan

Document Type

Response or Comment

Publication Date



General Principles, Criminal Responsibility of Parties, Aiders and Abettors, Appeals, Appeals From Conviction or Acquittal, Types of Orders, Defences, Res Judicata, Issue Estoppel


This is a case annotation of the Supreme Court of Canada case R v Cowan, 2021 SCC 45.

Whether issue estoppel should apply in this case is a challenging question. The majority's view is that principal liability and party liability are simply two different methods of proving a person guilty of the same offence, and therefore that a decision about the accused's guilt for that underlying offence cannot have been "final," as required, when it is overturned on appeal. In the abstract, that is not an unreasonable position. In dissent, though, Justice Rowe points out that the relevant question is not whether there is a final decision on guilt as a whole, but simply on some issue.