One of my best friends did something horrible and i don't know who's lying

Not sure if it's okay to talk about this sort of stuff on here, so feel free to remove this post if it breaks any rules. I don't usually go looking for advice online but I'm genuinely at loss as to what to do. A few months ago I went camping with 5 of my closest friends. That night we drank a lot and also got pretty high, and we all ended up turning in at pretty much the same time. Two of my friends, a girl I'll call T and a guy I'll call L, shared a tent between the two of them. A week after those events, T told me that L had tried to kiss her, but she refused her advances and fell asleep still clothed. However when she woke up, her belt was unbuckled, her fly was opened and her pants had been partially been pulled down. T is absolutely sure that L attempted to undress and take adavntage of her while she was sleeping. I confronted L about this of course, and he told me that it was T who had tried to kiss him, and that he just refused her advances and fell asleep. Now ordinarily I wouldn't stop suspecting someone just because they denied what they were accused of, but the thing is, I have known L for years, and he is the most respectful person ever when it comes to consent. His previous partners always went on about how he'd ask before doing anything remotely sexual with them. I've even seen him ask to kiss on of his exes before, so the story T told just painted L in such a different light, quite litteraly the opposite of the L I have know theses past few years. But T has been one of my closest friends for years as well, and there is absolutely no reason she'd lie about this out of the blue. She'd have nothing to gain from lying about it, and I know she wouldn't use such a sensitive topic just for kicks. I know something did happen for sure, because the one part of both their versions that match up is that one of them started making advances towards the other. None or my friends nor I saw or heard anything that night that could point to one or the other so the only two who know the truth are T and L. Both of them now hate each other of course, and I can't just stay friends with both, it wouldn't sit right with me to stay friends with someone who tried to take advantage of my best friend while she was asleep/someone who would use such a sensitive topic for no reason whatsoever. I haven't been able to sleep well for weeks because these thoughts have not left my mind since the incident. I doubt there will be any advice to clear this up since it could be anyone's guess as to who did what, but I'd still like to hear other people's thoughts on the matter.