The engine pings put it a long way from there and engine pings are a lot more reliable than someone who claims he saw something.
I wonder if that's true. Initially we were told the information sent to the satellites had location data. Later that was corrected to say there was no location data sent in those transmissions, they were merely "handshakes" indicating availability for transmission.
If that's correct then to make a guesstimate of distance from the satellite at the time of a ping they must be doing analyses of the characteristics of the signal received to come up with distance. Wouldn't surprise me if there is a huge fudge factor in that analysis.