The USS Vincennes shot down a regularly scheduled flight as well, after misidentifying it as a hostile even though they had other indications it was a commercial flight. In an earlier career I spent some time reviewing and taping AWACS mission displays of aircraft incidents, and even though our guys are very very good they sometimes make ID errors in the heat of the moment*. Generally they corrected them without catastrophic results from the misidentification.
Given that there was no benefit to Iran to shoot down one of their own airliners full of their own people without a way to pin it on somebody else, the positive (for Iran) reinforcement and mindset that came with previously shooting down a US drone, combined with an attitude like this:
still pushes the pointer towards "major screw-up".A senior Iranian commander who admitted to Iran's role in the recent downing of a Ukrainian airplane bragged in 2016 that even the youngest Iranian officers have unilateral authority to conduct strikes like the one that downed the Ukrainian plane, killing every civilian aboard, according to video obtained by the Washington Free Beacon.
https://freebeacon.com/national-securit ... wn-planes/
*In fact, this was my first recognition that eye-witness testimony is not necessarily very reliable. I would replay a mission for a weapons controller and asking him to explain what was going on while taping the mission display and his voice. We would let him run through it several times before making the final tape. I was often surprised at how much his explanation would change from the first run-through to the last, as he picked up on things that he hadn't noticed before.