Schwartz said that it may take some time for aviation investigators to figure out what happened since the plane crashed in a conflict zone that is not controlled by the government. However civilian and military radar data should be able to quickly determine the origin of any missile.
"There's always a risk when you provide this equipment to an insurgent force," Schwartz said, "which is why are reluctant to provide them to the Syrian rebels."
Loren Thompson, executive director of the Lexington Institute, a non-profit think tank on security issues, noted that the operator of the missile system probably made a mistake.
"A flight profile of a 777 would not have looked like a combat aircraft, but maybe the separatist didn't know that," Thompson said.
Even if the radar operator were trained, he may have misinterpreted data, according to Ted Postol, an expert in missile defense systems and professor at the Massachusetts Institute of Technology.
"Although the information is there to see, if you are scared and under pressure, you may misunderstand what is happening," Postol said. "If the operator is an novice he may not know what he's looking at. You know what buttons to push, but not much else."