Especially because one in particular should be trivial to prove - Wood appeared in a simulated sex scene in a music video (Heart Shaped Glasses). She has claimed that she is being raped on film in that music video (and has tried to get it taken down from online platforms on that basis). Given there would be a whole cast (the video has a ton of extras) and crew around for that and it was shot in multiple takes over more than one day there should be a mountain of witnesses one way or the other.
Problems here:
At the time the video was released, Manson himself was ambiguous and contradictory about whether it was simulated or not, but refused to concretely deny that it wasn't and, on several occasions, made statements that clearly implied it wasn't. Following Wood's allegations, he has concretely claimed that it was simulated. Wood, at the time, also claimed that it was simulated, but now claims that this was a lie and that she was pressured into making that claim. Also, bear in mind that there were certainly multiple takes and cuts in that scene and it's possible the footage used in the final video was indeed simulated, but that doesn't mean the events described by Wood didn't take place.
Some of the people who have come out to defend Manson seemingly haven't gotten the memo, because at least one crew member has come forward and confirmed that the sex was unsimulated, but claims that Wood, who was high at the time, came up with the idea. They also claim that Manson is a shy romantic who wasn't comfortable with the idea of having sex on camera. This is, to say the least, hilariously out of line with Manson's well documented behaviour and yet consistent with a common fan perception. Which brings us neatly onto who the cast and crew actually were..
According to Manson's statements at the time, there were two crews on the production. One was "his" crew, after all he was the director, and the other had some kind of disagreement with him over the sex scene. Now, we don't know what that second crew did or what their disagreement was. They might have just been editors who had no influence over what happened on set, but the key point here is that a significant proportion of the production staff on the shoot consisted of people Manson knew, had a professional relationship with or had otherwise hired himself. This may explain why a member of the crew is claiming to have insider knowledge of Manson's character and personality, but it also attests to the more relevant problem that any witnesses present might be motivated not to incriminate Manson or themselves.
Regardless, I don't think a defamation case is going to offer any kind of real insight into what actually happened. But here's the thing. I wouldn't be surprised if Wood got some details wrong. I also wouldn't be surprised if she isn't being entirely honest about the context of what happened and how she felt about it. That is normal within her position. Our culture is not yet ready to deal with the real experiences of victims of grooming, because they often don't present like stereotypical victims, and thus it's no surprise to me that someone in the public eye would seek to re-frame those experience as violent, forcible abuse because that is the only way they are going to be listened to. It doesn't really bother me and I don't really consider it a lie.
Basically, if someone references
Lolita in relation to their relationship with a younger partner, slam that person's face into the nearest wall, then find their partner and tell them that dependence is not the same thing as love, that being loved shouldn't be contingent on living up to someone else's fantasy, and to try and remember the last time their partner did something for them which wasn't accompanied by the immediate expectation of reward or reciprocity. Be sure to give them a number they can call if they're ever in trouble.