blindyboard, that may not be your experience, but it has been mine (women asking men and being rejected) and my friends.
I also don’t see a reference to refusing to buy a guy a drink. Most of the times, even if I do want to buy a guy, any guy, a drink, he’ll refuse me. Because they’ve been conditioned by society that they do not accept drinks from women, they’re the ones buying them.
Back to the OP, I am uncomfortable that some men are ignoring ambiguous signals in an effort to get laid, when there will be other chances, and those unambiguous chances would probably be better lays than someone who is not enthusiastic.
You can just go around accusing everyone of stealing from you, and somebody can go to jail on nothing but your say-so. It sounds like you’re taking issue with some bedrock concepts of the justice system, and fair enough, but I’m not sure these are issues specifically germane to this school’s affirmative consent policy (in addition to the fact that it’s not actually part of the justice system). There’s no special exception in play here with respect to testimony of the victim.
IANAL, but it seems to me that swearing contests (which I believe is the term you’re looking for) happen in crimes other than rape.
And no, victim testimony isn’t close to hearsay either. Hearsay doesn’t mean “testimony I don’t believe” or “testimony from a witness I don’t consider reliable”.