You are right in being angry. It was a disgusting act and the guy is clearly a loser who has no idea about women. But lets not get carried away with "What bad impression on a westerner?"
This behavior has nothing to do with whether someone is a westerner or not.

A similar thing happened to my wife in France last summer. My wife is a western French woman and the pervert was a white western man. Can't say if he was French or not as she didn't hang around to find out.

Point I'm making is that this sort of deviancy can and does happen anywhere.