He doesn't know what he is talking about. CGI was obviously used, as video shows the wing of the 'plane' partially in, partially out of the building, with no damage. That is clearly not possible.
The technology was also apparently used in the debate between Trump and Clinton. According to David Brock in the hacked chat, it was not Hillary at the debate. Brock would not elaborate how they did it, but was likely similar to what was done on 9/11.