Diplomacy has a place....last place. I start arguments and let someone else carry them through. Even a hint that I could be wrong sets them on a fruitless journey. That’s not to say that I’m never wrong but the usual violation that they want to argue about is a slam dunk. My reply is more like “go pound sand.” That’s not the wording but it is the gist.
When I suspect that I might not be right I research the issue. I have brought that to this forum. Sometimes I ask a question and with some I just post a picture to see what shakes out. As soon as I know that I am wrong I tell them. I do that even when I am sure that the correction has already been dealt with.
ICE, as a building official, I can understand why you would not want to preface any statement with "I might be wrong".
But as an architect, when the contractor has already told the owner "the architect has gold-plated the project with something that isn't required by code", and I know I'm right, I can still afford to be more humble, to make it easier for the contractor to eat crow later and keep things collegial.
FYI, when the contractor and I know that the building inspector is wrong, 80% of the time the inspector has just made a verbal comment, without a code reference. I tell the contractor not to challenge the inspector directly, but to blame me instead, like this:
"The architect has to justify the change order to the owner in order to pay for the fix, so he's asking you to provide a formal correction notice with a code citation". the problem usually disappears after that. If the inspector does provide a correction with code citation, and (for example) he's not aware that we've utilized a prescriptive exception, I can diplomatically email and tell him how we currently comply with code.
I never tell anybody to pound sand (unless the code issue is compaction, LOL), and I never just "go political" with a city manager or councilperson. If I can't defend my design via code, it's a failure on my part.
Lastly, I once had a project where it worked the other way: the contractor told the structural engineer that he might have undersized the window headers on a project in Lake Tahoe. The structural engineer arrogantly told him to "pound sand, you're just a framer, what do you know?".
The contractor reached out to me on the side. I have a built-in respect for people who work in the field and have an intuitive "spidey sense" about materials. reviewed the plans, found the engineer had only checked the headers for bending moment, not shear, in an area with massive snow loads. I called the engineer's boss, and the engineer was fired that week.