With the vic's face blocked you can't really tell whether he's just standing there or yelling some kind of smack at the locked restroom door leading up to the punching. Yelling at the door, or doing something else that is provocative rather than patiently waiting for his turn at the restroom, certainly wouldn't be justification for the other guy to punch him, but it would indicate that he had significantly reduced his 'resistance to selection for interference' leading up to getting punched, and may actually paint him in the light of interferior if he thought someone vulnerable was in there at the time.
