And of course the difficulty is this - does he know that what he is demonstrating is actually not what he says he is demonstrating?
alot of stuffs happened inside, so if folks just looked at the outer appearance, they would imitate the wrong things. I was on the receiving end of that sort of demonstration before. before the arms moved, he did the SJT #1 (sink the qi) then aikiage with his dantien/hara, then all the arm movements. folks observed would think that it was his arm rotations that made uke's shoulders did the crunching thingy. that wasn't the ki.
last year, Ikeda sensei was focus on the attack side in one session. he would reach out with both of his hands, grab my gi lapels, and yanked me forward and then pulled me straight down to me knees. that was what everyone at the seminar saw, because i looked around and everyone was doing it that way. Ikeda sensei did that to me three times. what folks didn't know was how i felt. it was as though someone reached inside my guts, almost like a punch from the inside out, pull me up, forward, then my guts drilled straight down into the floor. there were no yanking, jerking, pulling feeling from the lapels of my gi. I asked him to slow down on the fourth and fifth times. he did at 1/3 speed. i cracked up laughing. he smiled and walked on. i now knew how he did it. part of the answer i got from training with Howie Popkin. what you see is not what is.
if i haven't been exposed to IP/IS stuffs and worked on it for awhile to change my body, i wouldn't have felt what he did. most folks can't feel it. it is what it is.