A missile will look similar to a very fast moving aircraft with a contrail entering your path of travel. I only fly small planes but that would definitely get my attention.
Airliners are actually capable of some scary maneuvers. It could all have happened in less than 1 second and passengers just assumed it was a spot of strong turbulence.
I don’t doubt your expertise but I do believe it’s not germane to the facts.
Obama had the CIA take down the Russian airliner, perhaps with the coordination of ISIS, under the childish and mistaken belief that it would turn the Russian people against Putin’s efforts in Syria.
It won’t.