A checklist isn't complete until you say "xxx checklist complete". If you got an unacceptable reply, repeat the challenge or whole list if required. Do this a few times, and he/she will get the idea.

I flew with a nit-picker once. I told him I would monitor the rest of the trip. He asked me why, I said it seemed my technique did not meet his expectations, so I would watch and learn. After 6-7 legs, he decided I had learned enough, let me fly, and quit nagging.