There is an irony that you're adjudicating away other people's stress while holding up your own opinions and feelings of repugnance as evidence of a problem.

The reality of professional standards is we can't control what people feel or happens to them but we sure can put a good faith effort in to try and make the experience as neutral as possible. This April fools prank breached that standard in an unpleasant way. I hope there wasn't a student tired and on edge trying to meet a deadline. It'd feel awful to think the print system was out, spend a morning running around and then learn that some IT bloke was abusing his power out of a misplaced sense fun. It isn't a serious offence but it is bad behaviour.