You can bet your ass that, knowing there were going to be missile launches into Iraq, Iranian air defense batteries were placed on a “weapons free” status. Some moron(s) in the Iranian air defense corps, fearing an immediate retaliatory attack, were a little too trigger happy and unloaded on a “low-flying unidentified aircraft on an attack profile.”
You can also count on the fact that we know exactly what happened to that aircraft...
Good chance you are right.