Plenty of people are forgiven for small issues and as I saw you point out before CH is a prime example of someone who would of had tags removed after a few months of cooling down, but the verbal diarrhea that we end up reading ends up cementing the tags as accurate - I mean who would actually willing transact with that fool now?
I initially defended CH when he was first red tagged, and in response I got walls of ad hominem attacks and insults. I completely agree his ongoing immature behavior and trolling makes him far less trustworthy than his initial simple nonsensical posts ever did.
However, I still think that in cases like this we should all be reaching for the ignore button rather than negative trust. His behavior is driven by attention - deprive him of that, and he will stop. Too many people now have his original account on ignore, so he had to make a sockpuppet. Put that one on ignore too and let's all move on.
Speaking more generally, people who immediately start a thread and dish out abuse in retaliation for their red trust almost always end up with more. Take a break, take some time to cool off, and then come back and present a logical case. And as theymos has said, DT members should also be more willing to remove tags left for less serious issues.