I have also watched TII Billie Jean several times trying to realise what troubles me in that shoot. At firs I thought it was the playing with the sunglasses, after that i thought too there maybe also impersonator (real MJ has slimmer thies and longer legs ?). And i found the differencies in moving also. I think Michael done the biggest part in TII in directing, but he wanted to do part of the dancing and singin also by himself. I think there are impersonators in TII, you can see th difference how the crew is treating real mj and the impersonators, there is a huge respect to the real mj. I think it's quite genious really, altough the mj's seem and act very different, the large audience doesen't guestion anything beacause it is on the film
Maybe here is a lesson to learn, we must trust our eyes and ears and guestion when everything doesen't add up?