I find it much more likely that Iran, expecting possible retaliation from their attack, accidentally shot the plane down than the Americans did it to frame Iran. If the Americans had done it, I think president dip$&!# would be all over it and using it as an excuse to try to ramp up hostilities; which he doesn't seem to want to do today.
Of course but of the three scenarios, (accident, US did it to frame Iran, Iran did it accidentally), I have to go with the last one.