I have watched the famous New York UFO video over and over for several months now. I believe it possible the craft may be time travelling from the future...to see a WTC that no longer exists.

If you watch the tape, frame by frame, you will notice the distortion of the saucer image (no it is NOT cigar shaped) as it edges by the twin towers. This is consistent with the gravitational distortion which would be caused by such a craft.
The movements of the craft are erratic and wobbly, just as would be expected.

Merely because we don't presently understand this phenomenon, doesn't necessarily make the tape a fabrication.