IMO
We sell our credibility in every appraisal report we submit. On those occasions when I know I'm not hitting someone's desired outcome - which is often - I make the switch from defense to offense. At that point my goal is no longer limited to supporting why I think I'm right; I'm also going to actively set out to demonstrate why I think the opposition is wrong. Why I think that no reasonable person outside this transaction would consider their conclusion to be better supported by the data than mine.
I start out in my neighborhood analysis by getting more specific about it's composition and overall pricing trends for all properties therein. The subject usually fits in there somewhere. By itself that step alone imposes a barrier for the opposition to overcome when they claim a value conclusion that obviously exceeds the neighborhood's demonstrated performance. I do the same for my market segment (obviously in a difference section of the report)
I spell my dominant search parameters out in a little detail and comment that properties that don't fit these parameters cannot be considered more directly comparable than the properties which do fit those parameters. If I'm aware of a couple outliers I address them directly; I don't wait for the opposition to claim that I "missed" them.
It's like Conan said
Q: What is best in life?
A: "Crush your enemies, see them driven before you, and hear the lamentation of the (brokers)!"