The most popular theory of this tragedy is that an Iranian SAM brought the airplane down. I have seen no reason to disbelieve it, but still, a theory.
What I am a bit amazed by is the political readiness to assume it was done in error, not with intent. What possible evidence is there for such a proposition?
There have been news reports that many of the passengers were leaving Iran for fear of a war. The airplane had been delayed, but finally permitted to depart. Why was it delayed? Why was it important that it depart? What kind of decision-making was in play prior to departure and could there be any relationship to the decision to lock up and launch SAMs? Could there have been multiple Iranian government and military agencies involved with different agendas? Just questions, no assertions. Let’s remember though that solid evidence has not been provided.