they were idiots to put this issue in writing, should have been sorted in the carpark, followed by a quiet request to avoid being rostered together ever again. This sort of stuff happens in all airlines, but if the management get wind of it, you can expect the world to fall on your head, I'm afraid, cause they will be protecting their own butts before yours!
ps you can use the term 'paper-bitch' but you have got to be damn sure the guy/gal you are using it to has a sense of humour.