Yes it is, it's in the YT comments.

He used an emulator, I don't see anything about tool assist. Tool assists don't make as many mistakes as this one did usually, but I am still suspecting he used one.

I'm not saying this guy is for sure not using Tool assist, but have you not seen what is possible by humans in tetris: http://poetv.com/video.php?vid=23507

I'm pretty sure it's possible to get this far in nes tetris without tools.

That video is of a version of Tetris that gives a slight amount of time to wiggle the piece around, even after it's touched down before it actually settles into place and the next piece drops (which gives the player a tiny bit of extra time to get the pieces in the right place). In NES Tetris, there is almost no wiggle time--right after a piece touches the one below it, it locks in and can't be moved. Far be it from me to get into an argument over Tetris on the internet. I've gotten into the habit of assuming all incredible game footage is tool assisted unless it's obviously a screenshot from a real console, and even then I'm cautious.

Thanks Wander, I was looking for that video again.