Maybe. I can see why it would have been unwise as the kids might've taken him seriously. But at the age of 12 - 14 I would've thought most kids would know the difference between a joke and what's real. And I can't really understand his motivation for saying it, it wasn't necessary. But all the same, it's nothing to be horrified about IMO. As he said in the full article, you hear a lot worse in the playgrounds. Kids are saying these things to themselves anyway and it's foolish to think otherwise.