For the record, I was the one who issued the mute. First of all, let me say that generally I am very much aware about the issue of tone policing, and for that reason I want to allow people to be angry and express frustration within reasonably large bounds. See also for example me explicitly not acting upon Joepie telling Jonringer to fuck off months ago (n.b. see a pattern?), because of the context of situation which caused that statement.
You can also see concurrent reactions by two effectively asking for disengagement, followed by another message from delroth. (In retrospect, that may have been written earlier due to federation delays, but that is only of secondary importance.) In that moment, I saw a situation escalating further and the quickest way I could find to force disengagement was to issue a mute. Delroth immediately left the room thereafter.
In my moderation actions, I make a difference between actions targeting people and actions targeting situations. However this is a difference in intent, and may not easily be differentiated from the outside without additional communication. The latter is usually quick and temporal in nature, and thus only documented in rare occasions (imagine writing down every time a thread gets locked). The former is a lot heavier and usually takes a lot longer, especially since many actions require a wider team consensus.
In retrospect, I think I made the wrong judgement call in a heated situation. But more importantly, there was a communication breakdown, because there was no clarification about the intent of the actions taken. I deeply regret that this turned out to be the one drop too much for a person already on the edge of leaving.