Truth to power
A manager once got very upset that, in an email to him and him alone, I referred to a fuckwitted colleague as a fuckwit. (The context was "why did you slam the office door yesterday?" And the answer was "because I was debugging the script that was pushing the new AV sigs through several test servers and then pushing them out to a CDN to be deployed to hundreds of millions of endpoints under intense time pressure, as it had to work by 4pm, and the fuckwit found it very amusing to come up behind me during this time and flick his fingernail on my clamshell headphones very hard, and the third time he did it after I told him not to I had to go for a fag and a walk round the carpark").
Ten days later, a detailed discussion with HR after the manager lodged a formal complaint was brought to a premature end when I observed "Well, to be fair, he IS a fuckwit."