Regarding the theory that MH370 got close to SIA68 so as to transit Indian airspace without suspicion, it reminds me of a story I heard from a former RAF Lightning pilot who was based at Akrotiri in Cyprus in the late 1960s.
The Soviets were up to their usual tricks at the time and one of said Lightning pilots compatriots was scrambled to investigate an unidentified radar blip (just one). This turned out to be not one Tu-16 Badger, but two flying in a mirror formation, one high, one low.
I suppose that this proves that it can be done (in daylight), but I would be interested to know from any 777 drivers on here how they fancy a bit of night formation?