Russia, during the intervening months after the JIT’s May 24th presentation, had tracked down all of those serial numbers, 8868720, and 1318869032, and 9M38, and found (as you can see there by clicking on each, especially onto the “Briefing” itself) that after the acquisition of the launcher and missile, by Ukraine in 1986, from Russia, that missile and its launcher had always, and constantly since their transfer to Ukraine in 1986, remained in Ukraine, and never again were located in Russia. So: if the JIT’s supplied evidence is authentic — which the Ukrainian team asserts it to be — then it outright convicts Ukraine. This is an evidentiary checkmate, against the Ukrainian side.
I distinctly remember there was satellite imagery and radar substantiating that at least one Ukrainian fighter was flying right at the airliner (consistent with the article). Plus, there was a person working on the Ukrainian air force who said in a video that the fighters took off and returned right in sync with the imagery and radar logs. All of that was scrubbed from the mainstream Internet in the West. I'm sure the Russians still have it all.