Don't disagree with the recommendation to pay the appraiser at all. Would hope that the parties executed an engagement letter, which should have spelled out the intended use and intended user(s), as well as the effective date of appraisal. Under the assumption that the appraiser was aware of all of these items, the report should have been delivered in a format that the intended user could understand (e.g. no UAD verbiage). If that is the case, as the intended user, I'd look for support within the report for how the appraiser deduced the view (and/or location) adjustment. If it is not discernable/available/explained, I'd ask for clarification if I were the intended user. Something to this effect: "Mr/Ms appraiser, I have looked for documented support of your view/location adjustment within the body of the report. Could you please either (a) direct me to the section where you discuss support for this adjustment, or (b) revise your report to include discussion of your support for this adjustment." Should you need support for your request from USPAP, S1-6(a) and S2-2(a)x(1) might be helpful (assuming it was not a restricted report).