I assume this person is your sempai. Often from my own experience when this is the case I have found that the best thing to do is to copy exactly how they do the technique. It is not that they are necessarily trying to stop you from doing the technique, but that they have a preconceived notion of how they think it should be done. By coping them it will placate them and they wont resist you doing the technique the way they believe it should be done, otherwise they are completely hypocritical and ridiculous. You also learn a slightly different way of getting around power, and learn a new way to do the technique, all valuable stuff.
There is sense to what your are saying, but you and I are not talking about the same thing. You are talking about an experienced student who is trying to teach, and I am talking about an inexperienced student who is trying to win.