The accused was convicted of four counts of murder based largely on the testimony of an informer.
During the trial, the Crown announced it would call a corroborating witness but later declined to do so.
The trial judge prevented defence counsel from commenting on the missing witness in the jury address.
The Court of Appeal found this to be an error of law and ordered a new trial.
The Supreme Court of Canada agreed it was an error but applied the curative proviso, finding no reasonable possibility that the verdict would have been different had the error not occurred.
The appeal was allowed and the convictions restored.