Curative provision to be viewed from position of lay jury

R v Bishop 2013 NUCA 3, an appeal from a jury trial, has a useful comment on how to interpret the curative provision under the Criminal Code:

[142] In any event, the question is not how legally-trained counsel (or trial judge) viewed the weight of the impugned evidence. The question is how a lay jury may have. That is why the test for s. 686 is "may have affected the result", not "must have affected". Nor is the test "result possibly the same". The idea that this evidence could not have affected lay jurors because it is certain that they made narrow legalistic distinctions, or that they thought habitually shooting people was minor, is fantastic.

Discrimination so subtle is a feat beyond the compass of ordinary minds. The reverberating clang of those accusatory words would drown out all weaker sounds. It is for ordinary minds, and not for psychoanalysts, that our rules of evidence are framed. They have their source very often in considerations of administrative convenience, of practical expediency, and not in rules of logic. When the risk of confusion is so great as to upset the balance of advantage, the evidence goes out.

Cardozo J., in Shepard v USA (1933) 290 US 96, 104