This stuff is very rare, but tbh I don't find it surprising at all that women resort to this stuff when drunk. If she hardly remembers who you are or what happened, women being suggestible and quick to backward rationalize, she's going to easily get swayed into believing she was taken advantage of. Sex is something nobody should do in an unconscious or semiconscious state, it's a complete bypass of all the parts of her mind that would validate an encounter that she desired and wanted, and is therefore leaving an empty space for any perception to take hold afterward.
The fact that she allowed herself to be in that kind of position is unfortunate, but honestly I think most guys have enough sense to know making a move on such women is entering a situation that is already out of control.
For me personally, what makes me confident of not having to deal with false accusations is the fact that she has consciously bought into my reality and moved forward with me every step of the way through the seduction, and it has rewarded her continuously. The more someone consciously invests in something, the more they see themselves getting what they want from it, the more loyal they are to it and the more they defend it from negative perceptions. I lead her by the hand, I give her a great time, I cuddle and kiss her and talk to her afterward and send a nice parting text, I never pop the bubble we created together so that she feels able to continue to validate herself in it, and in defending it from outsiders.