The first plane hit at 8:46 a.m.  Bush's photo op begins at 9:00.  Just before entering Karl Rove tells him of the tragedy (9/11 Commision report).    If we are to believe your claim, the video would need to have been taken from the person shooting it and put on the air in the space of 13 minutes (the 1st crash took place at 8:46:40 and Bush enters the classroom at 9:00).