I don't believe she knew about his record. Maybe she thought it was a knife wound, but also thought that he had been the victim.
Right, the hairdresser didn't know his record. But didn't the girlfriend that was talking about marrying him know?
That's very true. Or maybe she didn't think of it as a knife wound until after she learned that he was a RSO that had just got convicted of murder and kidnapping. That would change my train of thought a little bit. haha. It's possible that she thought maybe he had some kind of medical situation/surgery or something. Which is pretty taboo to ask about when you're first getting to know someone.