This:
Age Discrimination
www.eeoc.gov
would seem to suggest you can not fire someone for their age. If you can prove that the perosn could no longer function properly, I am sure that would be different. Was Al providing the music in a timely fashion as he always had? Or was he now having a problem meeting deadlines?
Problem for Clausen is he will have to prove (not beyond a reasonable doubt, however) that age was the reason for his firing. How is he going to do that? If he has an email from executives at Fox saying, "we feel you are too old", then Fox is toast. Otherwise, how do you prove something like that?