Re: No more Mr. Nice Guy.
sounds to me like his ukemi is not good. If it was, he would help lead you as a junior student into the appropriate position rather than knock you over. If you could do it to him, I'd reciprocate since he set the standard. I don't allow my students to stop someone unless they are demonstrating a really poor posture habit. It's easy to stop someone if you know how they are going to move.