So I assume he is LT Plat - of which there are many.
You might call AA Advantage desk and see if they would do something - like send a appreciate note or something like that. No harm in asking.
Also - were most his travels on business at higher fares? Or personal low fares?
The airlines know the revenue difference and track it. He likely wasn't a big enough spender for Concierge Status, but maybe in a range above mileage runners.
No harm calling and asking.