Whatever the actual motivation in this truly appalling case the rough sex gone wrong excuse is definitely a huge danger, even if it was actually the case you still do have to wonder why this idea that this is what sex involves has taken hold and the only conclusion I can come to is the type of porn and the sheer availability and normalisation of it.
In the days I used porn it certainly wasn't violent, and yes I am not denying it was still harmful in that it objected women, but what is now being seen as mainstream to many young boys, and unfortunately also young girls, is not just socially harmful but absolutely physically dangerous.
You don't have to be the parent of daughters to worry about this but my goodness being so does intensify the feelings.
I can't see an easy answer, but I am sure that what answer there is surely has to not only equip young women in how to protect themselves but also educate young boys that this is beyond just bad behaviour.