Jabber it was much more complex than that as the following (from Wiki) shows. I think the only fair conclusion is that both shooting downs were dreadful accidents that happen in the context of conflict. Think of all the ‘friendly fire’ incidents that happen. I think there’s enough legitimate criticism to be levelled at both the US snd Iran over the years without implying that either would deliberately and maliciously shoot down a civilian passenger aircraft
‘According to the U.S. government, USS Vincennes mistakenly identified the airliner as an attacking military fighter and misidentified its flight profile as being similar to that of an F-14A Tomcat during an attack run; however, the cruiser's Aegis Combat System recorded the plane's flight plan as climbing (not descending as in an attack run) at the time of the incident.[24] The flight had originated at Bandar Abbas, which served as both a base for Iranian F-14 operations and as a hub for commercial civilian flights.[10] According to the same reports, Vincennes unsuccessfully tried to contact the approaching aircraft, seven times on the military emergency frequency and three times on the civilian emergency frequency. This civilian aircraft was not equipped to pick up military frequencies and the messages on the civilian emergency channel could have been directed at any aircraft. More confusion arose as the hailed speed was the ground speed, while the pilot's instruments displayed airspeed, a 50-knot (93 km/h) difference.[29]
This was finalized in a report by Admiral William Fogarty, entitled Formal Investigation into the Circumstances Surrounding the Downing of Iran Air Flight 655 on 3 July 1988 (the "Fogarty report").[6] Only parts of this report have been released (part I in 1988 and part II in 1993). The Fogarty report stated, "The data from USS Vincennes tapes, information from USS Sides and reliable intelligence information, corroborate the fact that [Iran Air Flight 655] was on a normal commercial air flight plan profile, in the assigned airway, squawking Mode III 6760, on a continuous ascent in altitude from take-off at Bandar Abbas to shoot-down".
The Fogarty report also stated, "Iran must share the responsibility for the tragedy by hazarding one of their civilian airliners by allowing it to fly a relatively low altitude air route in close proximity to hostilities that had been ongoing".[30]
When questioned in a 2000 BBC documentary, the U.S. government stated in a written answer that they believed the incident may have been caused by a simultaneous psychological condition amongst the eighteen bridge crew of Vincennes, called "scenario fulfillment", which is said to occur when persons are under pressure. In such a situation, the men will carry out a training scenario, believing it to be reality while ignoring sensory information that contradicts the scenario. In the case of this incident, the scenario was an attack by a lone military aircraft.[31]’
