Comes down to it that he was a dumbass and made a very poor decision in having sex with her. Too early to make a decision, without any evidence/trial.
Don't think she was raped, but a willing participant. Flirting led to a hug, then kiss. Then more physical and undressing.. Then her clothes/his clothes are off, Banging away. Nuts and he kicked her out when he was finished, thats when she felt used/abused and thrown out like the trash. This is a way for her to get back at his ass..