If he had an economy class ticket, then that is were he should have been! Too many free ride up front already. If he is unhappy, give him a $25 certificate good on his next full fare ticket!
If he had a first class ticket, then he should have been given a free ticket in 1st on a future rt flight.
That's my opinion. He normally flies another plane! He doesn't belong to AA's programs. How would an elite member of AA feel about being bumped out of first by such a coach vip class. Think about it, with you in mind as one who did not get upgraded because some diplomat had Ka Ka!