I think I just realized what's up with the inaccurate reporting:
From the start I had serious doubts about GPS operation in the airport--it would pretty much always have to be falling back to WiFi. WiFi doesn't provide actual location data, that's handled by a database of what routers were observed at what locations. Such databases have problems with WiFi sources that move around--a common example being cruise ships.
However, there's the issue of ad-hoc networking by Windows. How many "WiFi networks" are really just traveler's laptops--laptops that might very well be in another city tomorrow?