Maybe he genuinely is masturbating to depictions of rape, but that's not what it sounded like. You can have sex that is "nasty" and fully consensual.
I think there's a point your missing tiny. The fundamentals of the situation isn't whether the girl consented or not. She's crying & in pain. Whether that's great acting, so great it's horrified OP or she's being assaulted or she was fine up until that point where she wanted no more, they're all one in the same. The sex certainly isn't fake. It's the association. The video depicts abuse whether genuine or fabricated. If she's not actually being abused, the aim is to make the viewer believe she is.
Violence, assault, rape, aggression, insults they're what's associated with an unhealthy sexual relationship. The kind of things that tear people's lives apart. To be turned on by it is depraved.
If you're of the mindset that if its acting then it's okay here's another scenario..
If one of us was watching TV, and a woman was gang raped, she's crying and hurt. Dh is fighting the urge to masturbate during the scene, would that not be odd?
the things that turn them are often uncorrelated or diametrically opposed to what they enjoy in real life.
I can't agree with that, I doubt anyone thinks OPs husband is an abuser but it would appear that he is turned on by it..in real life.
The content of this video has appalled OP. This is her husband whom she thought would share her same pov on this.