For me personally, if you've been flirting look revealing etc, it's kind of expected. Because she didn't actually try to stop him or say anything it also gives the hint that in actual fact she was giving concession.. even though it says that he forced himself on her, giving that she had no reaction it somewhat indicates she was ok with it (on the basis of her flirting all day partying with him and they were both drunk- I assume.
I would rate it a 6-7 personally. on the basis that it was in fact rape.
The only 10 on my list would be anything involving children.