To start with the commentary is very odd, almost braindead ("oh my goodness, there's another one, oh my goodness, there's another one"). But the most telling thing about the clip is the consecutive series of zoom-ins (four zoom-ins total) right before the plane comes in-- the very wide opening shot shows no plane but when they finally zoom in very tight on the towers, all of a sudden the plane appears!!!!
I think this is yet more proof that the second plane was a digital fake. The plane SHOULD have been seen in the wide shot-- it only magically appears in the last zoom-in.
Many other second hit fakes here.