Anabasis, brother, I agree that things have gotten silly. But can it also be that you're taking this a little more personally because you want to believe in the guy?
I get that he PM'd you some good information, and I'm glad you got some value out of him, and I'm sure others did as well. But their is also a tinge of "wanting to believe", rather than a neutral assessment. AB summed up perfectly some of the psychology at play regarding the reaction of some guys to this whole thing.
A guy can give useful information yet still be a dishonest person unfit for a community. Pointing out that what he was doing was wrong and dishonest is not a dismissal of the useful information you received.
Objectively, he ignored a warning and continued a dishonest behavior. He's not a victim of misunderstanding or a mob, or a quick and dirty trial. He knew what he was doing, he knew it was not acceptable, yet continued. Lets forget for a moment the specific reason- ignoring a warning to stop doing something is reason enough for a ban.
I feel it's a little presumptuous of you to try and steer what is ok to post here. Even if he wasn't dishonest, NTP isn't some kind of deity that shall not be roasted with GIFs. Again, it seems you're feeling this way because of a personal investment. That's natural and perfectly ok. But what isn't is trying to dictate what level of respect needs to be shown, especially considering the guy has clearly lied.