By the time all error bars are considered INMARSAT ping estimates may point to lines hundreds of miles wide, or wider. It's possible the equipment has never been calibrated for this, meaning they won't know how wide the lines even are without careful and slow testing.
INMARSAT has release more information here. The techniques are in fact new and nothing is calibrated. However they analyzed six other flights that day ("predicting the past") and their technique got good enough agreement with the known tracks of those flights to give them confidence here. Good enough for an in-progress recovery anyway.
(neither Digi-Globe or Australia has stated *why* they looked carefully at images that far out in the middle of nowhere)
No way would pilots not report fire first before turning off electrical stuff.
Why? Reporting then will not help. Even a few more seconds of smoke may well hurt or be fatal.
Apparently, there's some people who are saying that the left turn was programmed into the nav computer like 11 minutes before the final "Good Night" voice message...
But.. they've gotten the timing wrong on so many other things in this investigation, that I don't trust much of anything I am hearing now...
The "premature turn" story has indeed been reversed.