Inmarsat know what they're doing. When they say how far the aircraft was from their 64E satellite at 11 minutes past the hours they can be trusted.
They're about the only originator of useful information in the whole saga.
Sadly, it looks like this could remain unsolved, unless someone has a lot of luck with a 43kHz sonar, or some international persons of mystery are willing to stack weather satellite/IR full-disk early warning images from the night of the flight or gets lucky with some archived radar data. Even then, it's going to be hard.
I hope I have to retract that, but two weeks on, it's looking like it'll be a long time before there's any more real news.