I already warned him about the very high likelihood of not receiving miles for the trip, the ethical issue, and the possibility of being black-listed. But he wasn't interested in any of that since he doesn't bother with frequent flyer programs. He wanted to do it so that could get the lowered Canadian fare without actually going to Canada. But I'm sure that he'll abandon the idea if I tell him that his itinerary may be cancelled, leaving him stranded off in Zimbabwe or who knows where!

Thanks for your replies.