Simon, I just noticed something in that video that seems totally incongruent.
Not familiar with the "16-SECOND MAGIC SEQUENCE", are you Steve?
Here it is on my website: http://septemberclues.info/wtc_airplanes.htm
And here's another gif I made of it:
But yes, your observation is quite valid. If you look at the "International Shot" (ABC), the angle of the towers doesn't look right - in relation to the "Ball" shot (NBC), where we see the 'plane' disappearing behind the towers far too early - with respect to its apparent speed and trajectory (if this sequence had depicted a real event in the real world, that is!) Whoever composited this 16-second animated sequence had a pretty poor sense for time/space/perspective.