Raine pointed out, "The problem is, since healing does help so much and so quickly, he may decide he's better off than he is and try to do something long before he should. Especially since he's inexperienced with having a human body and overly used to instant repairs."

It was stereotyping, yes, but she also figured that would be fairly typical for a teenage boy anyway. She especially didn't want to heal him only to see him hurt himself even worse.