The first tower collapsing was right on queue with the exiting of blackbird from the vicinity of the towers' rooftop. Black, white or other type, what legit reason is there for any copter to be hanging around a towering inferno?
Given the resume' of the man who recorded this, it sort of stretches the meaning of amateur but this is put into pretty clear / narrow context when the voice seemingly comes out of nowhere ... sounded like a bullhorn but could not see from where or whom these instructions were made but clearly somebody gave audible orders to the people standing there watching from the distance to stop filming ( somewhere after the first collapse and before the second ... Im estimating sometime between the 25 and 30 minute mark of this rare footage.