I have respect to those people, and because of not have been thrown by "no touch throw", I can not say if it is fake or not. There is a clip by O'Sensei's no touch:
if Watanabe Sensei's no touch technique is fake, then I think he must have learnt it from O'Sensei
PS: at the clip of Watanabe Sensei, below at the comments, a guy wrote:
"Great Video! I met Watanabe Sensei last year in munich and I had the possibility to attack him with a Suwariwaza Shomenuchi. He threw me over the mat without even touching me- i think he didn't even move. I never heard about his amazing technique before, so I was very surprised."
and also it is written that more info can be found at:
and interview at http://www.aiki-zen.de