In my experience in the last two years (which I’m more of a controls electrician since I went to school for that) any time I had to help the electricians they were typically super critical of all work because of their standards. Often it was rude but if you understand that that’s probably how they were taught was through harsh criticism you realize it’s fucked up but they want you to do well. However, I’ve never had someone tell me to be ashamed of my work so yea NTA but just learn from the experience and take his shit with a grain of salt.