1) the commentators sound totally phony, almost as if they were reading a script after the fact
2) this video came from one (suspect) source and has not been verified as legitimate footage by other sources; it is not found in other 9/11 compilations of network footage
3) the series of zoom-ins that are inexplicably oblivious to this plane supposedly racing up to the WTC-- the helicopter cameraman MUST have seen the plane long before it came into view in the camera (assuming the plane was real), but there was NO attempt to track the plane. Why isn't a second plane flying towards the south tower, after the north tower has been hit by a plane, interesting? (Ironically, this is EXACTLY the same behaviour shown by the helicopter cameraman who captured the other "live" footage of the 2nd hit, which was shown on CNN, ABC and FOX-- and it makes no sense that both "live" cameraman would act this way)
4) after the building explodes, something can be seen flying behind the building-- VERY FAST-- and then the camera quickly cuts away. What WAS that?
5) upon "impact", the plane's fuselage initially pokes through as if the plane passed through the building intact:
then the video feed goes dark:
then the fuselage is gone and there is just explosion:
Post-script: I should point out that Webfairy has a slow motion version of this video here, and also that this "Saltergate" video is one I tagged earlier as suspicious because there is an abnormal lag between when the plane goes "into" the building and when the nose comes out-- particularly in comparison to other 2nd hit videos. This suggests they didn't have timing quite right for insertion of the digital plane into the live footage.