It sounds like there are really two issues at hand in this scenario. One is the technical details of a specific job. The other is the larger issue of a potentially longer-term and larger-scope dynamic where one person (the inspector) will interface with multiple people (EC's, homeowners, govt entities, etc.) toward common goals (hopefully) of safe installations and operating conditions.
With that in mind, you may have some working details of a negotiating dynamic:
a) Common ground or interests (the community, the electrical industry & all its activities, etc.).
b) Common goals (the community's welfare as well as the safety of the specific location, the govt's risk mgmt viewpoint of preventing disasters rather than dealing with the aftermath, etc),
c) Differences of opinion which give you opposing or disparate points on a spectrum that also are fortified by each entities 'basis of power or influence' which may include expertise, reputation, official authority, etc. (Meaning that they have an opinion and their opinion has the ability to either push progress forward or prevent progress if a disagreement ensues.)
On this last 'line' of the triad you may find the nuts & bolts of the process to accomplish your mission - finding out how to have disparate points join efforts to meet the needs in a) & b).
Start by identifying the following:
1) where on the spectrum each entity seems to be 'stuck' or standing firm - their opposing or disparate points. NEC references are one way to describe their position - "meets NEC" or "exceeds NEC", for example. Identify as many points as necessary.
2) where the entities agree. This gives you some rapport-building points that allow each entity to agree that they agree and that there are points which build respect between the two entities.
For the disparate points identify the following:
A) where or upon what specific issue each entity draws their position
(like "GFCI" for safety in the event of xyz which pushes outside the normal operating limits of the system or equipment)
B) where each entity 'draws the line' - meaning what will they absolutely not give up or give in to and,
C) where there may be room for (healthy) compromise.
If you can find even some small ways to bring the disparate points to closer agreement you may find that the men have more in common than they realize or more reasons to respect one another's opinion and that with common goals in mind, working out the relationship issues is a worthwhile endeavor. If done well, neither party sacrifices their dignity or reputation or the quality of their work and they both get credit for increasing the quality of effort that goes into meeting the common goals.
