As someone who has over 6000 hours on the B777 as a captain...... and all of that flying international......... it is very possible to make the airplane go stealth while oceanic. This whole bit about the transponder is bogus as without active radar, it has no use. I've never flown over the bay of Thailand but have spent a lot of time over the South China Sea. Flown Tokyo to Singapore and Tokyo Bangkok many times. In the middle of the night, these control areas (Vietnam, Cambodia, Laos ) are virtually not existent. Many times position reports are "in the blind" and mostly for the benefit of other aircraft on the frequency. Yes, the aircraft is interrogated by operations on a regular basis but by the time anyone would sound the alarm bells that something was amiss, the airplane could be anywhere. Besides, to my knowledge these interrogations do not include present position. I'll have to check on that. Personally, I think the airplane is sitting on the ground somewhere.