Maybe the REAL twist of this movie is..... (HUGE SPOILERS)
...that there never was any rape.
Maybe Michele and Patrick had some sort of understanding that he could come over once in a while to do this rape thing. Because he needed it. And, more shockingly, because Michele enjoyed it.
It would explain the strange reaction of Patrick's wife near the end of the movie where she basically thanks Michele for helping him out for a while. She thanks Michelle because she was glad she herself stopped being the victim of her husband's agressive sexual tendencies and would instead go across the road to get his unusual sexual pleasure.
Which would make it consentual sex.
It also explains Patrick's reaction in the car as Michele says she's going to the police and tell them everything. He has a shocked look on his face and seems to wonder how she could do such a terrible thing.
Now to watch the movie in this light makes it even more disturbing because that would make Patrick 100% victim of murder.
Murdering their neighbours was already a big theme in the movie, right...? ;D
The massacre in the 70's father - daughter collaboration.
This time it's a mother - son collabtoration.
Damn this movie is demented...
"Yeah, well, that's just, like, your opinion, man..."