For me, the single most remarkable fact about the event is that communications were 'lost' at EXACTLY the most 'convenient' time to facilitate a 'disappearance'.
As Ian W has eloquently explained - when Malaysian ATC handed the flight off that was probably the end of their interest in it.
Before Vietnam was contacted by the aircraft they would have no urgent reason to suspect anything was amiss.
So, for only that initial 10 - 15 minute time period there was the perfect 'window of opportunity' for something to happen.
And it happened.
Right then.
How convenient! What a coincidence!
In fact, the time window was shorter in reality, because the NORMAL practice is an immediate transfer. So whatever happened had to happen within seconds of the handoff by Malaysia.
How INCREDIBLY more coincidental!
Well, yes, there may well have been a purely coincidental MECHANICAL failure/event at just that instant. Its possible.
But common sense and experience would tend to suggest that's so far fetched it is really beyond the realms of possibility.
Whats much more likely is that SOMEONE took an initiative at that ideal moment to carry out whatever plan of interference they had already prepared.
Does anyone still seriously cling to the 'mechanical failure' scenario, rather than the 'unlawful interference' one?