I was an instructor with the FAA. I taught students to be air traffic controllers in some of the busiest airspace in the world. It was intense one on one live traffic training that typically lasted for about 1.5 years for each student. It is infinitely more difficult than teaching someone to fly model airplanes. And guess what; on the first day of training, when the student is reluctant to open their mouth and transmit for the fisrt time, I always promise the student that I will not let them kill anyone. It isn't an empty promise either.

If you don't understand that the instructor is the person responsible for everything that happens then you should not be training.

If you cannot control everything that happens while giving instruction, then you should not be instructing.

If you think that "things" just happen that are out of everyone's control and it is nobody's fault, then you should not be instructing.

And if you believe that teaching someone to fly models is so difficult that the above don't apply , then you have lived a charmed life indeed. But it simply is not true.