Heyya
I agree with Jax. There is no rule requiring the wearing of a hat. The thing that irsk me the most about the gentleman you describe is the kids. Here we all know that the future, to some degree or other, of SASS shooting relies at least in part on juniors in SASS who grow into adults in SASS.
Sounds like someone, or several someones should tell this guy where the cow ate the cabbage. JMHO. If this guy isn't foolin around, or trying to be funny, and he is seriously getting after the kids then he is wrong.... and there is no reason for it, other than his need to be the hat police.
I think every club has one or two individuals like that. Not all of em are older either, they can be spread across the age spectrum of SASS members.