You and I know that intelligence agencies cooperate all the time, especially those of allies such as Canada and Israel. True, Chretien had to appear angered, but the fact is, I'm sure, that floating around intelligence agencies of democracies are plenty of false governmental documents from whatever countries' paperwork serves the need. CSIS isn't going to explain itself to you.
I am going to match your 'I am sure' with my 'I am certain' and tell you that if these guys had been caught in some illegal action (and why else would they use someone else's passport?), it would have all come back to Canada, and that is, after all, what they were there for, is it not?
In reviewing the comments by posters who say they are more loyal to Israel than to Canada, I have to look at this incident and ask them: do you think these Israeli terrorists should be able to hide Israel's guilt behind a Canadian passport? And if the answer is yes, then I have to ask, how stupid do you really think we are here?