As far as I remember that scene anymore, he was just stupidly sitting in his chair, looking at Murasaki give a lecture to the punks as if it had nothing to do with him. Now, what the hell was he even thinking at that point? He was hired to take care of her in the first place, so why didn't he go after her the first moment he noticed she started to badmouth some violent punks? The punks themselves didn't want to argue with a little kid, if you have a relook at the scene. If at that point Shinkurou had quickly fetched her away, nothing would have happened. Things started to get bad because he went in so late that one of the dudes (or two already? I don't remember) was already standing.

You know, if you show a dog you are afraid, it will only encourage the dog to become even more bold. If he had just coolly walked there, grabbed the girl and said "sorry about that" and walked away when the punks were still just being annoyed and surprised by being lectured by a little kid, they would have likely just forgotten it ever happened. That's what I meant with the 90%. But he went there like a weakling and started that whole submissive apologetic behavior that served little purpose.

I don't know. Maybe he has some problems because his work oft includes beating people up. Maybe he feels he needs to be roughed up himself, sometimes, to retain his karma or something. If it's like that, he should just drop the kind of work he's doing because it'll only get worse for him before long. It would likely make him an alcoholic sooner or later, so that he could forget what he's doing.