looking at temp? so if a WX has temp thats ok?
Let me explain, and I think your example tends to confirm my guess (and I am only guessing).
I don't think WU is looking at anyone elses data, just the station in question. (if I'm right, people stressing about cheap eBay stations skewing things can relax)
I think they are analyzing each stations historical data looking for unusual variations outside of some norm. When that happens, no more gold star. Your example station is way off from everyone nearby but if you look at the graph of their data (forgetting the 50 deg discrepancy) it's nice and smooth, and when adjusted matches other stations.
They may be looking at things other than temp but I don't think they're comparing my data with other nearby stations.
Again, I'm only guessing. YMMV