Mary: Good point - and I think we agree.. Especially that nage in the case in question went way beyond what a good sensei should do. The highlighted part of my post was intended to say that sensei any - while striving to create a good learning environment for each and every student in the dojo - sometimes have to push the students out of a state of 'Heck - I'll just stick to what works for me' in order to help them evolve. It might well be simply by showing them that what they sink they now is more complex once they get to a point where they are able to grasp it. As a sensei we are not all-knowing, but with more experience should follow the intention to understand the students and try to assess what kind of training would be best to help them move along.
Anyway... I think we agree (mostly)