If I was caught like that I would send you an apology, taped to a box of doughnuts and I would go back and amend my inspection report.
You can't stand up when you are right if you refuse to back off and admit when you are wrong.
I have to admit I had not seen that many gray PVC boxes before but I was never confused that they were metal. I just wondered if there was something different about them. In the end I figured out Slater just decided their boxes should be "slate" colored to differentiate them from Carlon.
Otherwise "same old, same old".
It did help me a lot that I had the time to talk to the contractors about things like this and I really enjoyed the banter. I understand the time pressures on your usual Muni inspectors may not allow that. That is also why I prefer the electrical contractor trade organization (ECF) that has inspector members more than the IAEI that is just crusty old inspectors.