According to ABC News:
At a June 30 Pentagon news conference, NATO Supreme Commander Gen. Philip Breedlove said Russia had been providing air defense training to Russian separatists on its side of the border with Ukraine that focused on “vehicle-borne” surface-to-air missiles.
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“What we see in training on the east side of the border is big equipment, tanks, APCs, anti-aircraft capability, and now we see those capabilities being used on the west side of the border,” Breedlove said at the time.
He added that the anti-aircraft capability training focused on larger vehicle-borne missiles instead of portable MANPADS.
“We have not seen training of MANPADS,” Breedlove told reporters. “But we have seen vehicle-borne capability being trained.”
NATO General Warned of Russian ?Anti-Aircraft? Training for Separatists - ABC News
If that June 30 date is accurate it supports the contention some 'separatists' had recent training in vehicle-borne systems and access to them, and at some level Russian military/intelligence knew it as well.
It may also fuel the debate on why airlines continued to traverse that area. Would only NATO members specifically be advised of the increased risk to commercial aviation? Would the decision-makers at some airlines even understand the significance of vehicle-borne missile systems versus MANPADS?