An image has a lot more information than an audio tape, and a moving image has still more. That makes it a lot harder to avoid leaving clues that would reveal a fake.
That said, if your tape was the video equivalent of the recent audio tape (that is, if it looked like it had been shot by moonlight in the fog with a hand-cranked camera loaded with old film stock), I'd suspect it of being a fake delibarately shot in such a way that it would be hard to find the flaws in the low-quality image.