That guy was just asking for trouble. Unless this was an adult bookstore (or adult section) I'd say that he was way out of line and that the girl could reasonably expect that such encounters would not occur regardless of what she was wearing. If I was the girl dressed as she was entered a bar or similar location, then the opposite would be true. There should be some expectation that men would try these things...I mean isn't that why you dressed the way you did in the first place? For attention? Usually from men?