The jerks probably just watched easy Rider. I can't believe what some people do for "giggles". I'm glad the rider wasn't killed. He even managed to stop it by himself.
I met riders from Houston, a good twenty five years ago, who carried side arms. That was long before Texas had a concealed weapon carry law. Houston drivers had a reputation for putting bikers into overpass guard rails back then and, reportedly, the mere sight of a .45 could restore their better judgment.
My experience riding in Houston is limited but I've never had a problem there.