Alright so, I had the displeasure of joining the server due to your valid calladmin, only to nearly immediately hear you make multiple and very noticeable remarks to other players telling them to kill themselves. I merely warned you at first that such disrespectful attitude to others was very much against our server rules, directing you to the motd when you claimed there was no such description in the rules.
I then went to try and sort out and handle the various issue that were occurring, during which you constantly attempted to claim your statements of telling people to kill themselves was in fact not disrespectful, which I told you a good half a dozen times over was the opposite of the case. Plain and simple, telling someone to actually kill themselves or otherwise issue death threats to others is not, and never has been, tolerated in the slightest. Instead of accepting this you choose to attempt to argue to that such behavior was just fine and did not fall under the concept of disrespect to every extent you could, refusing to cease what was a very mute point in an argument that had no reason to exist and only could stir more issues. Your refusal to cease after several minutes despite multiple explanations is what resulted in you finally getting muted, and your continued comments and further disrespect is what resulted in you getting gagged.
To address what happened with your friend, he was slain just before his warning to prevent him from further attacking people outside of his spawn. It's commonly done when one is killing inside the spawn as well, to prevent the situation from escalating as quickly as possible.