Looking at video footage, can this be seen through body movement, training methods, mechanics etc of Ueshiba Sensei or not?? What is it that can be seen? How do proponents of today's aiki know this immense skill was present??
A further question I think might be an interesting follow-on Chris' question: of all the things we can see Morihei Ueshiba doing in his publicly available videos and second-hand accounts of private happenings, just because he did it, and we can't, does that automatically make it aiki? And the things he taught explicitly to his students, does that necessarily make it aiki, or just the curriculum he taught to them based on what may have been a circumstantial background knowledge to understand something he wanted to explain later?
Or put another way, do we define aiki as merely what aikido does, or is aikido a larger grab-bag of teachings, only some of which have explicit utility in expressing aiki, if any? What if he regarded his students as so remedial that he basically had to spend 99% teaching them Martial Arts 101 before he could spend 1% of his time teaching some of them what he really meant? And yet, what if that remedial knowledge is still so far above most of us that it seems just as profound? i.e. the separation of aiki from the notion of internal strength, or of internal strength from efficient body mechanics, and so on, ...