I think they both messed up, however, I'm more on Ryouma's side than Izumi. That guy already git hands with Izumi once, during their first meeting, and he knows that he was constantly sexually harassing Ryouma. Yes, Ryouma overdid it, but Izumi is making light of it when he shouldn't be. Or rather, not taking it serious enough. And while he should be mad at Ryouma, Izumi should also know where he's coming from because of everything I've already pointed out.
"I'll stop laughing when you stop bleeding."
~ Unknown
~ Unknown