By this logic, if someone is drunk, it's not their fault for driving, either, since they weren't in the right state of mind to be making that decision.
People do dumb shit that they sometimes regret when they're drunk. They might make decisions they might not have made otherwise. But they can make decisions. A drunk girl can consent, and she can refuse as well. Just because it tilts the odds doesn't mean it's rape if she wishes she didn't do it in the morning.

