Watch your back

Strange incident at the pub over the weekend. I wuz haffing some pints wif me mates (cockney), and my friend made the comment: "It's a sad scene," in regards to something we were talking about. So this girl who was standing nearby walks over to our table, leans over and puts her face about 3 inches from his and says: "Did you call me an assassin?" My friend recoils slightly and says: "No, but I am kind of afraid of you."
"Okay," she says, and walks backward slowly, smiling madly and eyeballing all of us.
I mean, even if we did, is it that much of an insult?