So, the question I have is, does an underwriter have the authority to act on intuition alone, or does the underwriter have to follow written rules and guidelines like the rest of us? My experience tells me it is the latter.
Doug,
Evidently this UW feels you have failed to support your opinion of value. I don't know where you personally draw the line between "intuition alone" and "written rules" but IMO this situation is not that cut and dried.
The word "credible" is part of our written rules but there is not a written list of specific actions that make a conclusion more or less credible. USPAP says your analyses must be credible. If your client thinks it is not (rightly or wrongly) then IMO it behooves you to address the issue.
Many of your peers believe the sales comparison analysis should include a range of properties that sold above and below the opined value. We believe an analysis that does so tends toward more credibility and one that does not tends toward less credibility.
USPAP does not include the details of methodology of the sort that is found in textbooks. But credibility absolutely depends on use of those methodologies.
Only you (not us because we have not reviewed it) can opine whether your report was credible. Frankly, given only the sketchy info posted here, my first impression is that it sounds like you over valued. If I read the report, I would likely feel otherwise.
If you want to dig your heels in in defense of your report and are willing to let it continue to be considered "unsupported" by your client then that is your business decision.
This is not quite the same thing as an UW asking for additional comps without citing a reason. The UW has cited a reason that seems appropriate to a good percentage of your peers.
It's really not a question of what the UW is "allowed" to do as long as they are not asking for something unethical or illegal.