This clip is from Jay Zimmerman, who also captured the same falling man that was captured by Jack Taliercio. The falling man was also captured by Kevin Segalla:
Many people say the footage of the falling man is fake, however if that's the case, then Zimmerman sure went to a lot of trouble to add footage of dust and paper pouring out of a building that, a few minutes later, would disappear into a cloud of dust and paper. The footage is real. The dust and paper are real. And the man really fell.