No one was ever run up on war-crimes charges in the downing of Iran Air 655 back in 1988, and there the USS Vincennes had not been under attack by an opposing air force, the plane was on its usual route, not hundreds of miles north of its usual route. Nor, although payments were made to the families of those killed, did the U.S. ever formally accept responsibility for the downing of the airliner. Even at the edge of war, fog of war exists and can lead to unintended civilian deaths.
If Putin's government wants to deny responsibility, they have adequate precedent given them by the U.S. government. In fact, Russia can follow the precedent exactly: wait eight years, make ex gratia compensation payments to the victims' families of $300,000 per wage-earning victim and $150,000 per non-wage-earning victim, will still denying responsibility.
If international law is not simply to be a bludgeon with which the U.S. (or the winnner in some conflict) beats opponents, it should apply equally to all.
If Russia provided badly trained rebels with those SA-11s then they are as guilty as targeting the civilian airline themselves. They were the ones giving live grenade to a monkey and had to expect there are chances their monkey might mess things up.
You examples is wrong because the USS Vincennes was not conducting unlawful warfare. Russia is. And there’s a pile of statutes under international law that will hang them for it.