To get removed from NG would require one of the following:
1) Posted Something Illegal (in this case I mean a flash you stole from someone else, or hate crime promoting flash)
2) Illegal behavior on the forum
3) Start a fight with an admin
I HEAVILY doubt it was case 1, which really only leaves 2 and 3. This would be consistant with the fact that his account has also been banned, which serves as the deletion date for all his movies along side his ban. If Square-Enix had went on a CT-Sprite Movie takedown tirade, I would have also been hit movie wise (but both of our accounts would still be up). I don't know exactly what he did, but judging from the way he'd sometimes textually scream at people on NG who gave him negative reviews - or sometimes just criticism - I'm going to guess he finally screamed at someone he didn't realize was also a mod.
The preceeding was only a guess, but it is based on having been a long-running member of the NG community with an account dating back to 2001.