A summary of the investigation by the US Central Command said proper launch procedures were violated in the incident, but said the chain of events that led to the downing began with an "erroneous" detection of a hostile threat that turned out to be the F/A-18.
The friendly fire incident, which claimed the life of Lieutenant Nathan White, occurred April 2, 2003 when two F/A-18 were returning from Iraq after a mission to their aircraft carrier in the Gulf.
Their path took them over an area where a Patriot missile battalion had been deployed to suppress Iraqi missile attacks on coalition forces.
Late in the evening, one of the Patriot batteries detected what appeared to be the approach of a hostile Iraqi missile.
The battery notified their superiors at the army's air defense network's coordination center of the detection, called the Information Coordination Center (ICC).
"However, this hostile missile detection was erroneous," the report said.
"The ICC incorrectly correlated this erroneous missile track to the track of one of the F/A-18s and identified the second Navy plane as an unknown threat," it said.
"Within seconds of the initial report, a second Patriot battery located closer to the frontline in the path of the F/A-18 also detected it as an incoming Iraqi missile," the report said.
Judging from the "missile's" track, the second battery concluded that it was the target.
The two seemingly corroborating reports convinced the ICC that US forces were directly threatened by an incoming Iraqi missile.
"The ICC ordered the targeted battery to launch status and two Patriot interceptor missiles were launched," it said, adding that "proper procedures for obtaining launch status were violated in the process."
"Both the Patriot missiles located and intercepted Lt Whites F/A-18. The plane was destroyed and Lt White was killed. The second plane returned safely to the USS Kitty Hawk," the report said.
The report said "appropriate actions" were being taken to protect both coalition ground and air forces in the future, but did not describe them.