I think I remember someone saying that all koryu have within it a form of "kotegaeshi." I guess it's not a very tough technique to figure out and incorporate into a system...
That's a really interesting one to comment on and it does seem to show up a lot in other forms I've watched. We seem to be the only ones who do it with the idea of connecting it to center. Most other's seem to be of the idea that you grab the wrist and twist really hard. If uke slaps like a wounded duck you did a really good job.
Of course, there are those upon whom that doesn't work very well.