Interesting discussion here, if we replace the technical terms by Tomiki's terminology we are discussing in that case how to come from simple basic techniques to sparring. In Tomiki's randori we are using a lot of atemi, not to knock down someone, but as a tool to throw someone. Kaeshi waza is possible on techniques which are not done perfect. This is the case of George Ledyard.
In a videoclip of Takeshi Inoue http://www.youtube.com/watch?v=Cr7zLwiWhdg
we can seen many kaeshi waza. This kind of randori is called hikitate geiko which is a flexible randori style.