As soon as I saw this thread, I thought of this...
https://www.stuff.co.nz/national/117826699/embarrassment-after-obscene-language-used-in-official-council-letter-drop
I know the guy that this happened to, so met him later that day to buy him a couple pints to drown his sorrows. It sounds like a simple office prank from one of his workmates blew up in his face.
Fortunately everybody, including the residents were very understanding and no one lost their jobs.