The only problem with going to Cuba through Canada is what if you accidentally lose your passport or have a medical emergency or get robbed or whatnot. No embassy or state dept. to help you out, so you're pretty much just staying there. Not to mention what happens the next time you try to travel and they see the stamp. Good story though.
Now let's hear about the time the waiter forgot to let you smell the cork and it turned out to be the '82 not the '81. LOL, we really had it out with the sommelier that night. Oh, well, just another day in the life of us steely, gung-ho adventurers/soft core porno mongers.