Well, that is not very bright of either party involved. I would say that for something to qualify as rape, lack of consent should be provided. Unless it is clearly forced, or it was clear to the consenting party that lack consent could not be given.
A guy can get pretty horny, although I know i will always wait for consent(or more likely, lack thereof), i am pretty controlled. I think it is reasonable that women have to indicate when there is no consent.(so should men, of course) I would not have sex with someone who is drunk, given i do not have some kind of relation of the kind with her.
Anyway, a priory there is no evidence that the girl did not consent either. It is his word against that of the girl. Innocent until proven guilty. (any jury basing a conviction based on only this is a set of presumptuous idiots, in my view.)