As I said, this isn't an isolated incident. It's not everyday by any means, but it's not unique either. Sexual mutilation is a horrible crime and it's horrible some women think they're justified with this response. Perhaps even worse is women who praise such actions.
The issue at heart IMO with any kind of destruction is about immaturity and self-esteem. There's the view that your partner somehow "got one over" on you, you've lost face, and a destructive response, be it mutilation or destroying game CDs is not only good but necessary. There's a country song that's been popular here for some time, perhaps some of the foreigners may know it also:
Carrie Underwood - Before He Cheats I've always thought this was a horrible song that glorifies overreaction, immaturity, and ignorance. She sings about trashing her man's truck because he MIGHT be cheating on her. Maybe. It's part of the Jerry Springer syndrome: screw communication, diplomacy or understanding, throw something11!!!