I'm a well read grad student who's bluntly honest about all things, although I try to be most honest about myself.
Look, I don't think a movie forced him to do this, or that he wasn't violent before this. I don't think one sees a movie, and just goes, oh, maybe I should beat up and rape a woman. But I was googling to see the date, because one of the Amazon daily deals is A Million Shades of Gray and I wanted to see which was published first. (A million shades, it looks like.)
The first thing that popped up? This. Even if he lied about his motivations, it ties the book and movie to this assault because he used it as an excuse for his actions. I wonder what E.L. James has to say about this...