JANE'S, la prestigiosa publicación sobre inteligencia y temas militares, dice que casi seguro que fueron los pro-rusos:

United States intelligence sources confirm that the aircraft was hit by a SAM, while former Soviet and Ukrainian air defence specialists in Kiev told IHS Jane’s that this missile was either from a Buk unit controlled by the Russian-backed rebels in Ukraine’s eastern regions or possibly from a battery located on the territory of Russia itself.

The Ukrainian military “has no Buk systems in this part of the country any longer”, said one former air defence forces officer. The Buk units that were based in this region were taken over by Russian-backed separatists on 29 June when they overran a Ukrainian military installation. The separatists posted photos of their new acquisitions on Russian social media on the same day, but deleted these internet postings on 17 July as soon as it was clear that the aircraft downed was a civilian airliner and not a military target.

The same former air defence officer also pointed out that the Ukrainian military has safeguards in place to prevent this kind of an accident from ever occurring. “There is a datalink from the civilian air traffic control system that monitors all commercial airline and civil aviation flights," he explained. "This input into the air defence command provides full coverage of all non-military flights, so it is nearly impossible for a Ukrainian armed forces unit to have brought down this airliner. It is almost certainly one of these rebel bands operating in the east of Ukraine, operating with Russian assistance and simply shooting at anything that passes over their heads.”