Thats the most important question: What are they covering up and on whose behest?
In addition to cover-up, why are they misleading the entire world. They knew all the time that plane is not anywhere in or near gulf of Thailand / south China Sea. Then why did they mislead?
I certainly think there is some awful media relations work at foot there, but I've managed aviation SAR incidents (post Sep 11) where we could not disclose information from classified military assets that were being factored into our search plan. Some of these assets make the oft mentioned here "primary ATC radar" look like a joke.
We had to be circumspect to avoid a public disclosure rabbit hole... it was also an incident that was subject to a lot of media coverage.
I almost accidentally mentioned one element during a media interview, it would have created a major issue in terms of cross jurisdiction cooperation for the future. It is possible either their own military or foreign military has provided them information on the condition that the source and type of information not be disclosed, hence the skewed search area (from day 2?) with no explanation. The SOP is to say "we've received information from a variety of credible sources that has led us to move our search in this direction".
The standard SAR methodology is to work from your highest probability of detection areas down. It appears they are doing that. This is usually based on imperfect information, e.g. they have a military track but it is partial and may not connect with the ATC track (and therefore identity of a/c). Or they have clues that are credible but wrong, which misdirect resources.
Ironically we were going to be meeting soon with one of the government SAR departments involved in this search, I assume due to this incident those meetings will move out a bit. Of course I'm going to try to get the scoop on what went on (when all this is over), but it will be the very last thing I ask them in the meetings; I'm sure there will be reticence to discuss.