@9190 Londonman.
We cannot know that assorted radios etc were swtched off. All that we know is that, for example, the Transponder/s stopped giving out info, and none of the VHF radios transmitted any more, nor did the ACARS perform later on. We have no info that says 'Radios were switched off'.
And we still don't get to see the cargo manifest (which of course might not be accurate, in that some 'goods' might not have been manifested), nor have we got any access to the military radar records of several, probably useful, surrounding nations - as well as that of Malaysia itself.