I took the time to investigate what happened. The Devs were fairly candid and straightforward about the matter.
The fact is that the upper echelon of CCP were away on vacation when T20 committed his actions, and the person who handed down his punishment (yes, he was punished over it) chose to step lightly and not fire him, rather than risk overstepping his authority.
The misconduct and punishment happened over 6 months ago. Firing him now over it would be just as much of an injustice as his original breach of conduct. It would, in essence, be punishing him a second time - and more severely than the first time - for the same offense.
CCP has put in much more stringent internal affairs protocols since it happened. Getting up in arms over the fact that T20 wasn't fired (especially if you're implying that there's still Dev corruption going on) is just simply overreacting.