I read about it this afternoon. I don't know anything about the movie, so I can't offer an opinion as to whether this controversial scene fits and is appropriate to the film or not. My only opinion, based only on the director's words, is that, yeah, the scene is beyond disturbing, but so is real life, so it does exactly what she set out to do - disturb. The people who are screaming about it are right wing religious zealots who prefer to sweep things like child abuse and csa under the rug, unless is suits their agenda that is. Therefore, I pay them no mind.
If you fall down 10 times, Stand up 11.