Does the protester have a right to disrupt an event?
Obviously, two wrongs do make a right but there are many cases where rights collide.
Punching the idiot was wrongish, but I just can't see acting out and then playing the race card anytime there's a consequence.
Nope, they do not have a right to disrupt an event.
But let the proper authorities take care of the situation.
Unless the guy was physically threatening someone, the audience should not be physically assaulting them. Its not their job. Leave it to the authorities to take care of the situation, unless people in the audience felt their life to be in imminent risk.