Can anyone explain what causes this:
Clearly this UPS aircraft did not land on top of the terminals. It did indeed land on the runway a couple hundred feet to the south of that path. And once on the ground, it continued to report a position that was offset a bit and was a bit "sketchy". The real taxiway he exited on is actually off that image to the right.
This happens to about 0.5-1% of the flights I see.
And it's not MLAT (in my config, the lat/lon in the selected box would be italicized if this were an MLAT position).