Thanks, Mr. Ng, for the sound advice.
I always avoid teaching during class. It is disrespectful to the instructor. Hence, in the incident cited above, I forgot to pen that the 3rd-Kyu asked me why his technique didn't work and I took the opportunity of being the nage to explain to him while doing my technique. I assure you that there was no disruption or annoyance to the class.
A wise sage once said, "Humility comes with suffering or pains". I learn it pretty well. Look forward to train with you, my fellow MA (learned from your posts that you do karate & Shaolin). Where do you train?