Sure for his experience & position yes, which is where he should have drawn the line. However he starts making wild accusations while being unnecessarily aggressive and insulting particularly without understanding is crossing the line to being civil.
I have never given a job to an operator that I would not do or haven't done myself. If I thought a setup or person could get hurt then I wouldn't run the job at all or as an owner I would run it myself.
If repetition and safety is an issue as it is with any long running, repetitive job, they have to be worked out. Some people are suited for repetitive work and some are not.
Tom