So... what if the situation were just a tad different.. Let's say it was an Indian guy who is a tech evangelist for a successful startup and two guys behind him in a "private conversation in the middle of a crowded room" made jokes about how indian people speak or act.

Those are jokes, and totally unprofessional in a work environment where you are representing your company that is sponsoring the event, right?

But we should let that go because he was wearing shorts and t-shirt instead of a suit?