I've been called FAR worse things over the years by users.
I would have taken chummy aside and "had words", maybe go as far as a scare-the-bugger-half-to-death, but dobbing him in like that ? That's just cold.
Anyway, I have room to talk about bad behaviour on placements - I was blind drunk by 10am on the day I was supposed to meet my placement supervisor for the first time. Okay, it was my 21st birthday, and yes, THAT was my "present" !