That's 100% rat damage along the back, there.... that's what they do, tear them up along the spine like they're eating an ear of corn. It's horrible. Your guy was actually extremely lucky that the damage was relatively milnor, I've seen photos of ball pythons eaten down to their spine and ribs. I don't think he was deliberately abused, she just left a rat in with him - probably with no food or water, so it attacked the snake.