I got in an argument with our shop manager because he said he made sure that he had shimmed a plastic pipe round using a pair of calipers to make sure it was the same diameter all the way around. I pointed out that the shape could be and likely was a trochoid that will measure perfectly on diameter with a two point measuring device, but can be very far from round. He claims to be a precision machinist but didn't know what a trochoid shape was, which means he really has no idea what round is.
I was of course completely correct as shown by the documents I presented to him and my boss but I got asked to work from home for two weeks to keep out of the way! He can only hide incompetence for so long.