Please point out the post where I made any reference to paired sales (or any other specific technique).
When I look at reports performed near the same time but with a 50% difference in value conclusion for the same property (which I have done numerous times over the past 15 years), the most common finding is that one of the appraisers ignored the most similar comparables sales, choosing instead to use the sales that are very dissimilar and then failing to adjust for differences in location, quality, condition, etc. in an appropriate manner.
If one is appraising an older, non-renovated home, then it is easy to jack the value up by choosing nearby renovated homes and ignoring the fact that they need quality and condition adjustments. That is a problem in executing the methodology, not a fault of the methodology itself.