It sounds like you need to mind your own business in the gym. Honestly, if that works for him, what are you complaining about? I have written how I train on this site and some people act as if it is impossible that I am making gains. Perhaps it is you who needs to think outside the box every once in a while.
How do you know it was exactly 36 reps? You counted? Over how many sets again? I assume you know this right off because instead of focusing on your own training, you were engrossed by someone else's. Is it not possible that you mistook something said? Why not give the trainer this website adress so he can defend himself instead of you doing it for him?
The point is, I see nothing HARMFUL in what you wrote.