I agree but I would never be friends with my rapist...
It's understandable honestly, it mostly comes down to the individual person and how relevant they consider to be what was done to them. If they don't think of the damage they experienced as something very deep, then who would I be to tell them they should "give it more importance".
Like for example, someone who lost the ability to walk due to an accident, only they know how relevant that incident was to them, if they can talk lightly and joke about it, then cool, I'll respect that; if they prefer not to touch the subject because they consider it to be a sensitive topic, I'll not mention it then, and I'll also respect that.
I would give jihyun a second chance ONLY AS A FRIEND, because if he has really changed and I can really see it, I'll accept it, but I could never really 100% forgive someone who not only assaulted me but also DESTROYED the possibility of having a football (or soccer) career. He could NEVER EVER, become my best friend (or even more impossible, a lover), but I could never abandon him for real knowing that he really put all of his efforts into changing, plus that he was once a very good friend. I personally am bad at completely abandoning someone I once cared about, when I know they want to change for the better, because I like to believe people can really change.
So I don't think chiwoo should just stay away from him, but he shouldn't pretend they can be friends like before, because that is just impossible in many ways.