I seriously doubt that any of the radar equipment at or in the vicinity of the airport would detect the most likely missile culprit -- a small, shoulder-fired IR (heat seeking) missile (many thousands of which are unaccounted for around the world, btw...). Air Traffic Control "radars" aren't really radars at all, at least not in their primary operating modes. They actually function as "interrogators" that cause the transponder in the aircraft to respond with a data signal, which the system's computer converts into a "blip" on the controller's screen. "Skin paint" mode, the most degraded, semi-functional capability is what you think of as radar, and they're lucky to catch all the airplanes when that degraded, let alone small, fast missiles.
My guess is that it was an idiot with a signal flare or some other such thing. At least I hope it wasn't more.