I can appreciate the question, but I cannot speculate as to the factors that were in place.
I can say with certainty that the embargo was in place and there was every expectation that the Canadian government would have known. If exports continue despite an arms embargo, there are only two explanations. One is willful blindness: They knew, but didn't act on it. The second is, perhaps embarrassingly, that we didn't know when we've should have known.
Neither one really paints a positive picture about the strength of our export control system.