This is the known track of MH370 from transponder returns up to 17:27 UTC
therefore we need to invert the Burst Offset Frequency data to get a correct sense of MH370's progress either east or west.
Flight east is a decrease in Doppler frequency offset (reads down).
Flight west is an increase in Doppler frequency offset (reads up).
If we cross correlate Doppler shift with the timeline corroborated by known direction before 17:27 UTC then there is no way on earth it flew west from IGARI.
When the aircraft was at the gate at KUL airport at 16:30, the BFO was 87 Hz, and at that time the LOS speed (due solely to the satellite motion) was about plus 0.021 km/sec. At take-off at 16:41 the BFO increased to about 125 Hz. This therefore gives us a datum line or longitude to measure if the flight went west or east.
What it shows is that until at least 17:50 UTC it continued to fly northeast (over Vietnam or along the east coast) and at some point after 17:50 UTC it must have reversed course not detected until the handshake ping at 18:25 UTC.
The steepness of the plot line after 18:25 UTC might be explained by the fact it had already flown back west some distance before 18:25 UTC giving a misleading graphic representation.
This is an extraordinary snippet of information because it reveals the Malaysian Authorities misled the investigation suggesting MH370 flew into the Straits of Malacca and all previous assumptions therefore are based on wrong inputs by the Malaysians.
This also makes plausible the long discarded sighting of oil rig worker Mike McKay on Song Mercur of an aircraft on fire for 10-15 seconds west of his oil rig.
The most generous thing one could say is the Malaysian Government did not understand how to interpret the Burst Offset Frequency data and UK AAIB who advised them were pretty clueless themselves.