Vlad, as I see it there are two basic approaches to dealing with a "weak" inspector.
"The Stick" is where you raise a fuss with his boss, take the citation to court, and so on. Or, have a trade association do it for you. The problem with this method is that is does nothing to prevent the guy from having another "stupid attack" in the future.
"The Carrot" is where you introduce him to the internet, to this site, as well as a few others. You make sure he gets word of IAEI meetings. You make it require a dedicated effort on his part to remain ignorant.
As far as the water pipe goes, tell him "that's not a ground wire, that's a bond wire to remove any electrons that might enter the plumbing if some fool uses a hair dryer in the shower!" If you can't dazzle them with brilliance, baffle them with BS.
