My reading on the SA-11 is that it would need an early warning radar unit with it. It is a radar-guided missile and the target radar would have a range of about 20 miles. That means they have an engagement area of about 40 miles if the airplanes flies right over the top of the launcher. Smaller engagement are the further the airplane is away from the launcher. The plane was probably going around 600mph. That is 10 miles a minute. That puts the plane in the engagement area for four minutes if it is flying right over the top of the launcher. My reading says that it takes a crew five minutes to prepare to fire. If the plane is in and out of the engagement area in four minutes, then it’s unlikely a crew could get off a shot without having an early warning radar.
That leads me to think it was Ukraine or Russia.
The author of the article is correct that Ukraine is probably the only one to have a somewhat plausible reason to intentionally shoot down a foreign airliner. But, the British press has been reporting that there was a Ukrainian military transport aircraft in the area.
I think the most logical explanation is that the pro-Russian rebels accidentally shot this airliner down thinking it was a Ukrainian military transport. It was either a lucky shot, or the Russians warned them. I don’t believe in luck.
Enhanced BUK group is three vehicles including loader and command and controls but launcher is pretty capable to work on it’s own as it has a built-in radar.
Five minutes readiness is not a time needed to engage aircraft upon detection. It is actually a time needed to deploy system upon arrival to the scene.
BUK is basically a regimental point-defense weapon, made to protect ground forces from missiles and light fighter-bombers in an area of their deployment. It’s primary idea to restrict airspace over ground troops completely and for that reason target recognition is not the strong point.