Re: ineffective technique from sensei?
It might be too big a step to 'confront' your teacher. He is clearly struggling with his experience with/view of his teacher. First question yourself, then the other. So it is wise to get informed the best you can and prepare well. He merely vents his experience, does not really judge his teacher, only questions him.
Would he in front of the class confront his teacher, this would be a challenge and he would possibly undermine him. But...I agree the best is to talk about with his teacher, one-on-one. Builds character...