"Construct an argument" for my position is exactly what happens and is expected when a board of appeals or a judge in court hears a case. If technically I cannot issue a building permit on an amended application, whatever the judgment of the bench/guard might be, then I can save the owners and the jurisdiction time and money and I consider that pragmatic.
And you are right that it is a professional opinion, and that opinion can be based on the background and experiences of the professional and not only on facts in the numerical sense. This is what I understand interpretation to mean. If there are numerical facts, there is no longer (or, less of) an element of interpretation. I can use my background and experiences in life to interpret that a convenient built-in standing surface that essentially reduces the "guard" height to 24” can be considered an attractive nuisance for anyone under the age of 12, (and perhaps for many over the age of 12).
If the board of appeals has a collective mind from their background and experiences and they overturn my decision, that is fine. I don’t expect to have all of the answers all of the time.