This speculation is interesting. If, as others have written/speculated (and I'm typing this on the fly and admittedly not referencing/sourcing, so I'll own up to any errors/misremembering), Ueshiba's core art was Daito ryu where he started on the path to developing his body skills, then later supplemented with additional/other exercises involving the sword and spear (later modified to jo) and even (possibly) qigong-derived type body work from his religious studies/experiences, such that in his later years, his practice was uniquely his own.
Perhaps, by the time Tohei was developing his own practice under Ueshiba, what he was able to "feel" and "see" regarding Ueshiba's skills (I think I remember reading that somewhere in an interview Tohei mentioned learning most from Ueshiba was the ability to "relax") based on his observation was something that he was able to connect to in the manifestation of Ueshiba's religious qigong-derived bodywork (even if it didn't seem "martial"). No doubt Tohei was also able to connect the "relaxation" with the "release" into incoming forces that Ueshiba was able to demonstrate "martially" in his own practice. As a result, Tohei may have identified and used these different "building blocks" to get to a similar result in his practice, even if he wasn't being explicitly "told" how to do it.
Anyhow, I'll be the first to admit that I don't know enough about any of this stuff to have a definitive opinion either way, I'm just tossing my speculations into the pool since I don't feel like working right now
. Additionally, I'm interested in the "paths" these greats have taken since they all seemed so keen on seeking out and/or "stealing" this information.
Lastly, to semi-relate it back to the thread topic, I've heard very good things from friends that have trained with Ki-Society folks regarding the way they isolate and train some of the bodywork, so it's high on my list to get to one of the seminars in the next couple of years.