One of the significant comments in this article is: Reuters said the military radar data seen by its sources
Reuters is not revealing sources. It earlier spoke of a rift between US and Malaysian investigators. It's become a common comment that Malaysia is obfuscating, perhaps to save face.
However, this seems deeper than that. Reuters sources almost certainly are US.
Going over the Andamans, the choice is between landfall in Bangladesh or Burma (Myanmar). Myanmar would be a candidate for terrorist activity, perhaps.
The airliner was highjacked between 1am - 130am early Saturday morning. By 6am they were far away from the Straits of Malaysia. They could have refueled and been out over the IO without anyone looking for them. If they went over India then they probably used false ID but I do not believe they did that. It has been six days since they disappeared with no one looking for them the first 36 hours. They might have stuck to open ocean, far from land.
My supposition has always been that they headed for a large landing strip on the Maldives Archipelago, then onto the Middle East. No one last weekend seems to have been looking for them in the western IO.