An acquaintance, now gone, was a nurse to a brief Campeau hospitalization in the late '60's. She reported that Bob insisted that his minions confirm that Pierre Trudeau wasn't a homosexual before he would agree to meet with Trudeau or donate to his campaigns. 
I always thought his constructions were mediocre at best, his business practices duplicitous, and his reach consistently exceeded his grasp.  Among Canadian business entrepreneurs, it seems to me that only the Reichmanns (Olympia and York) exhibited hubris on a scale exceeding Campeau. Just guessing, but I expect it was trying to compete in the Reichmann's league that led to Bob's comeuppance.