Our western culture is very trigger happy and the problem with not hearing all of (both sides of) the story is that it is easy to jump to conclusions.
Big question is not so much what was the issue but how was it dealt with.Did this guy start throwing his weight around/become abusive etc.If it was a polite request on his part he should try to remember her name and take it further.If he is one of those guys that enjoys belittling people who he percieves can't defend themselves he should wind his neck in.