"...that one of PwC’s ballot leaders, Brian Cullinan, had pulled the wrong envelope from the pile to hand to Mr. Beatty."

Except that there was no pile because it was the very last award and all the other envelopes had already been handed out. There's ways to administrate this sort of thing so that mistakes don't happen, and sometimes people who are new to the job underestimate the amount of attention to detail needed so that your delivery is truly impeccable. I wonder if PWC had someone new setting up the envelopes this year.