I've seen footage that suggests that the plane is cgi. I know how that building is constructed and theoretically what would happen to a plane that crashed into a building of that construction type. The fuel tanks are in the wings... wings wouldn't penetrate that building. It's hard to say. Also that footage you linked, the 'plane' supposedly came from the other side. That's why the explosion comes out all the other 3 sides. The momentum of the fuel smashing through the building. According to their theory. I don't really have a better theory other than a basic understanding of how materials interact. I suppose it's possible that the wings smash into the building, smash the exterior, and momentum carries tons of jet fuel through into the office where it explodes.