they really should look at not overflying any war zones. Having said that, apparently there were at least 2 other planes quite near by at the time as they'd reportedly been routed there by ATC.
These 'war mistakes' with terrible consequences happen (and I hear these missiles can reach twice that height). Remember when an American navy idiot shot down the Iranian civilian airliner? Lead to Lockerbie and a lot more.
What is revolting is the way that the local authorities (rebels, Russians, whoever) are responding. There's denial, cover up and a total lack of respect.