Mises,
But, the current location is shorter than the previously estimated position for a KNOWN TIME 8.11, which was based on a slower speed. That's impossible.
Not impossible at all when you consider that the only thing they have to work with is the Doppler shift values.
When you have only the Doppler shifts, the only thing you know is the speed of the aircraft RELATIVE TO the satellite. You don't know the distance between the two, and nor do you know precisely the track of the aircraft.
You can estimate a track, based on an assumption of the aircraft's true speed. If you assume a different speed, however, then the entire track direction changes, as does each ping position along it.
If the estimated track had stayed the same, then I would agree with your "impossible" claim. But note that they have come up with a new track.