Traditionally this would be solved by inserting a comment into the code that insults the user (for example the classic "The user is a wanker" comment [1]).
> Shit. I was just about to launch into an explanation of our code review procedures. Every week we sit around a table and carefully and dispassionately analyse and constructively criticise each others code. And it works. We sit there and listen and take it all in. It works really well and team morale is excellent. One day we're even planning to do one when we're sober.
Sometimes you just have to put your foot down and just say "No, that is not how you use this tool".