An issue of trial fairness is raised if a judge fails to address an element of an offence. If an element is overlooked, but the evidence overwhelmingly proves that element, does it matter that the fact-finder did not make a finding on it?
The significance of the omission will need to be assessed in the circumstances of each case. Trial fairness is not simply a procedural matter. If it was, the answer would be the same in every case. But trial fairness has substantive meaning: the law must be accurately applied to facts determined impartially.
In R v Khawaja, 2012 SCC 69 (14 December 2012) an element of the offence had been overlooked, but the error did not affect trial fairness:
"[93] This is an exceptional result, appropriate in the exceptional circumstances of this case. Generally speaking, if an appellate court finds that the offence for which an appellant was convicted includes an additional essential element, fairness would require ordering a new or directed trial. In this particular case, however, this Court can be confident that the appellant suffered no prejudice deserving of a new trial only because the evidence on the additional element of the offence was overwhelming, as indeed the trial judge found, and it is plain that the appellant's strategy would not have changed had the element been recognized at trial."
A misunderstanding of this would be that the ends justified the means: if the person was obviously guilty the error could not affect the fairness of the trial. What the Court means here is that the error did not affect the impartial determination of the facts because the defendant would not have conducted his defence differently had the error not occurred, and the defendant was not deprived of a real chance of a more favourable outcome.