Inmarsat pings
I find it strange that investigators talk about two possible routes based on Inmarsat pings. These are not routes, but merely candidates for the final resting point (+/- one hour's movement).
My understanding is that the satellite logged the signal round-trip time, which allowed to calculate the distance between the airplane and the satellite. So for every one of these 6 pings, there is a ring on the Earth surface where the airplane must have been during the ping. The portions of the ring that are too far away for the fuel load are cut away, and so we get the curve on the map as shown by investigators.
From the 6 pings, there must be 6 different rings. But we are only shown curves from a single ring (probably from the final one). Is there any information about the other 5 pings? It would at least help determine the lateral motion of the plane (how much it moved "towards" or "away" from the satellite).
If all 6 pings had the same round-trip time, it probably means the plane stood still (maybe flying a holding pattern until the fuel ran out). It is very improbable that the plane was programmed to fly a curve that would keep the same distance from the Inmarsat satellite for hours. This isn't a Great Circle route at all.
Unless of course the whole Inmarsat story is a cover for a leak from intelligence sources.