Re: a teaching mistake
Hi, this happens to all of us and it can be a good thing. When a technique does not work, for whatever reason, it is an opening and an opportunity for learning. I really love it when sensei takes the time (and he often does) to explain in detail what makes a technique work and what makes a technique fail, even to the point of explaining what to do if & when a technique fails - "ok, now you're here, what do you do" kind of thing. Showing the technique on different uke's is very helpful, not necessarily in order to find an uke who "knows what to do", but to illustrate that people are different and an uke looking like schwipsenegger is not the same as one looking like Kate Moss.
Showing techniques that fail are not mistakes but a natural and necessary part of aikido teaching.
Big new year's mile to everybody