This clip is from Charlie Rose. The video is played from sometime before the first crash. The VO says something like 'huit heures quarante-six' as the video shows someone using test equipment on a vent.
You then start to hear the sound of the jet engines. It must have been very loud, based on the altitude and open throttle. At 1:30 into the video clip, the fireman in the centre of frame looks up at the sound and appears to be tracking the jet (not yet seen on the video). Initially the camera operator stays on the fireman, but at about 1:35 pans over in the direction the plane is headed.

16 into interview, he remembers looking up and seeing the plane fly between two buildings. He indicates that he was holding the camera at chest level)
1:43 after just catching the impact and quickly zooming in on the fireball, he zooms back out all the way and then in and out again
1:53 camera wavers quite a bit, very unsteady.
There is no evidence at all to suggest that this video capture of the impact is not what it appears to be.
There is nothing inconsistent with the story of the firefighters or the Naudet bros and the video.
Attempts to disparage the Naudet bros, the firemen or the video are purely malicious speculation not based on observable facts. They should be treated as such.
They bring shame to those who make them, and disrespect the integrity of those witnesses with no good cause.
http://www.youtube.com/watch?v=TCHSQPv65Jk