” they told him to remove his unfamiliar headgear.”
There was no reason for that request.
He was stopped because he had a flat tire — what does his headgear have to do with that?!
It was unfamiliar to the cop. Attitude or not from the cop, he was entirely within his authority to ask him to remove it, both to better identify him and to make sure he was not hiding something dangerous underneath it.
I rode a Hog. Lots of times the cop said straight off to remove the helmet. Wasn't a big deal then, but if you need to wear your fez at all times so you are not embarrased in public do not expect any sympathy from this side -despite how much I detest arrogant LEOs.