Crumble - apple or rhubarb?
The whole Inmarsat edifice seems to be crumbling. Sadly.
They have previously stated that they have round trip times for the signals. This I understand very well as I am a data network engineer as my day job. I have been measuring network delays (let's call them) for decades.
Now they appear to be saying that they do not have those times. They only have the "offset" times. These are the differences between the times expected of a notional satellite and a notional aircraft and the actual times measured.
As far as I recall they have not released the position of the notional (I refuse to use the inexplicable 'nominal') satellite. They have not stated how they think they know the position of the notional aircraft.
They of course know where the notional satellite was. But they do not appear to know where the notional aircraft was. So any offset from the round trip time from the notional satellite and via the notional aircraft is meaningless without further information about the location of the notional aircraft.
I of course must be missing something - hopefully.
At present I have no inclination to even start on the BFO.