To Roving:
First, according to the URL you put "The U.S. official cautioned that the assessment is not final and that U.S. analysts are still investigating".
Second, I wonder how such a statement could be proved. First, the rebels and the regime army units are mixed in the region - one village is in the hands of one side, the neighboring one is in the hands of the other, and so on. Second, the Buks are mobile. Thus, to say such things for sure would only be possible if the (independent third party) intelligence is chasing and monitoring the activity of the particular Buk complex. This is only possible on the ground. Neither AWACS, nor satellites could do that. They could only roughly estimate the point of fire and the type of a missile.
Third, if this is coming from the same US officials that earlier were saying that the homeless Ukrainian refugees were relocated to the neighboring/adjacent Russian region to breathe the fresh mountain air (actually all this area is flat and dirty cause of coal mines) or that the US should move its fleet to the shore of Belarus (which well is isolated from the sea), then arguments make no sense.