I think the difference was more of him being filled with holes when he bit L-Elf.
I was talking with someone earlier and I remembered that the green haired girl saw them kiss and asked if it was intercourse. There is also an episode where she talks about insertion. Perhaps the girl controls Haruto when he gets like that to some degree. She was freaking once Haruto got his mouth on Rukino's breast at about 21:16 of the episode. Maybe she was using him as a test subject, or she just really wanted to see Haruto have intercourse. She could also be feeling what he feels but that would be really weird.
My problem with the rape was that we know Rukino could subdue him in one kick. She did it like 10 minutes prior. She didn't even try. Haruto doesn't seem to gain super strength when he goes berserk given how easily he has been stopped before. He must have though. His hands never went below the belt so he must've gone straight through his pants and underwear as well as her panties.
Edit: Rukino made a promise to kill Haruto this episode. I guess the time skip will be about her and the others going to kill him.