And now that I think about it, since AA seems to be the airline of choice for sociopathic people with mass murder on their minds, I don't blame for being freaking paranoid.
YO, when he boarded the flight his paperwork was properly filled out. When he got bumped to another flight because of a mechanical problem, he went to the flight personnel at the gate. They did not have another form and Airline personnel crossed out the flight number for him and replaced it with the new flight #, etc. and passed it back to him to give to the captain. That was unaceptable to the captain and somehow the airline was then able to come up with additional copies of the form. He didnt sign one of the forms and rather than tell him to sign it, the captain had him fill out another. The dispute was not over whether he was who he said he was but over who had the bigger ego.