It's Not the Nose of the Plane
If the CGI "no-plane theory" is correct and it's the nose of a computer generated plane animation that can be seen exiting the opposite side of the tower in the FOX Chopper footage, then why doesn't the nose hold it's shape? The alleged nose can clearly be seen morphing and expanding as it exits. An animated plane graphic would not do that, especially if it was an editing blunder that was never intended to be seen.
Below: The exiting "nose" is compared with the plane's nose prior to impact.
See how it was done: