Sorry but this shows that you don't understand the method of transmission in Japanese aikido. It is very clear (in Japan, at least) that during a class there are two lessons being taught. One is for all those watching, this is how we move our hands and feet, etc. The other is for the person taking ukemi, this is how it FEELS.
Prof. Goldsbury can certainly explain what he meant if he wishes, but I wonder if it might not fall on deaf ears if you don't understand the distinction in the first place. The idea is that O'Sensei expected correct ukemi because he was transmitting something directly to that person, not because he was interested in showing whether he could do a technique or not to the peanut gallery.
It is a nice theory, but today everybody agree that O sensei didn't teach, and even wasn't interested at all if anybody can learn something from him. It works against the idea that he wanted to pass some knowledge to his students.
The fact that somebody wants to FEEL a technique from him and adjusts his own ukemi for that goal, doesn't prove at all that that requirement comes from O sensei himself.You are trying to inverse a logic here, sorry.