A dear friend of mine had been a pro for 60 years or so, and near the end he told me that if he gets too old to do a good performance that I should tell him.He did not want to be a "Back stage pain in the ass." I promised him I would. Didn't have to. He realized he was over the hill and he quit on his own.He didn't live long after that, performing was his life.

Maybe someone should record that old man's set and play it back or let him take it home. If he has any awareness left he will know it's time to call it quits.If not, some kind soul should tell him.