The pilot reported technical problems before crashing. The aircraft was at 33,000 feet. Only states have SAM systems with that kind of range (i.e., no shoulder-fire SAMs).
Unless it was shot down by a nation’s military unit I’d be included to think this was a mechanical problem, and had nothing to do with any kind of missile attack.
“included to think” should be “inclined to think.”
I strongly suspect Lockerbie style sabotage.