Out of the three as much as I am a skeptic. Murder suicide by the pilot is my first punt that I would willingly enter discourse and the Americans are the second where I would use the phrase "yeah it could be true but come on why would they do that". But then, we have well documented behavior on how non-American loss of life, their local culture shift and consequences of American actions is irrelevant to the US government throughout time for their own gains. Russians on the other hand, I ain't calling them angels but they never caught the first metro for colonialism to establish themselves around the world, What are they doing in that part of the world? But again no debris? So it makes so no sense for the plane to be shot down there + Vietnam/Malaysia/Thailand would capture 3 planes flying so close to each other.
Coming back to the topic, the plane ultimately needs to be examined post the turn in Malacca. India has a naval+air force base in the Andamans so I would assume it did not go North from that point (rendering the dumb Russian take moot unsurprisingly from an American) else they would have called it out considering their non alignment movement of not being a coward to the big powers that they keep doing. The main takeaway for me is that Malaysia made a huge mistake waiting 4 hours doing nothing and then were obviously clueless for every moment after that considering most important maneuvers happened in their air space.