Funny. But sad.
My eye surgeon, a world famous doctor, who also flies his YAK in formation (24 inches apart, he tells me), stopped performing eye surgery after he turned 70. (Although he still maintains his practice behind his proropter.)
His hands seem steady enough. Whether he was forced to stop because of Insurance or whether he chose to stop out of prudence, I don’t know. (Unlike flying when too old, he won’t end up crashing and killing himself if he screws up a surgery at his age. But he will screw up his “passenger.”)
I say that he should stop flying his YAK in tight formation too.
But go ahead, let a 70 year old surgeon work on you. And go ahead and fly with a 70 year old in close formation. Let’s see how your movie ends.