I’ve been an inspector on public works projects, You have to be able to read/understand ALL of the drawings, read/understand all of the applicable codes/specs and the manufacturers’ info. The most common excuse I heard was, “We’ve always done it that way.”
I worked on public works projects for 40 years. Some of the inspectors really knew the business, could cite a lot of stuff right on the spot and make a decision right then and there. Others, not so much. They had to go “research” anything you asked them. The slightest alterations from the plans required meetings and time to think about it. It was easy to tell if they knew the construction business or if they just walked out of a classroom and had never had dirt on their hands.