It sounds like you're nitpicking the physical aspects of the positions that she must have been in, and when you can't make sense of it, want to throw out her entire story. In fact, if he IN ANY WAY pressured her to have ANY KIND of sexual activity AGAINST HER WILL, then he is in the wrong. If he was emotionally abusive, he is in the wrong. There's no point, in my opinion, in nitpicking this, because we were not there and thus cannot make a good judgement.
It is very likely that she has perfectly valid reasons for wanting to divorce the guy. However, in a general sense, I concede that in any divorce proceeding, distortions could certainly come up, and you run into a "he says this and she says that" situation. And this could happen from both sides.