I'm not going to comment on the frying pan other than to agree that is domestic violence. Since you said "once" it indicates it was not a current event.
However, if a guy comes up to you and says he heard some erroneous (up to this point) gossip, I would only assume your wife told her friend "something." She may have said she discovered you're visiting this site or others. How does that translate to her leaving you? Ever play telephone as a kid? Maybe your wife said she was thinking about leaving you over cross dressing, etc.
You may want to ask your wife what she said to her friend because so and so came up to you and said what you related here.
