Yes there are plenty of different methods that appraisers can use to detect sales. I am sure you have seen plenty of good appraisals and some not so good appraisals and have been able to locate questionable comps in appraisals.
Let me restate the obvious then. Based on the sales price of this home verses the sales price of surrounding properties that are similar sized and would be considered comparable properties by any appraiser or realtor, in no way do I believe this sale is or will be, considered a comp. Regardless of whether the sale was found in the tax rolls, or on Zillow.
I would also speculate that based on how the transfer was done, that there are other factors involved in this sale.
