Unfortunately oiramoric you do not see what transpired since we don't post all the PMs and messages involved in a situation like this. Hrattle did indeed recieve multiple warnings over a period of days, including several that warned him that any further such behavior would result in a ban. He just continued to escalate the issues and became more insulting.
Then a series of PMs between hub leaders circulated to discuss his issues several times.
Thus, everything you suggest was done.
If you are suggesting a public warning, I cannot agree, as it would just serve to embarrass the poster. There is no mechanism to temporarily suspend a poster to enforce a cool down period. That might be workable, but you would need to discuss it with Agoracom to see if they could change their system to accomodate the change.