First of all, condolences to those who lost loved ones. This shit is always political, and about assets and intrigue, and hubris, but it is also enormously horrible for those directly involved–The dead, their families, and the AA gunners who hit the wrong target.
Summary: Israel wants to blow up some Syrian stuff. As is protocol, untargeted forces (in this case, Russia) are warned in advance of the operation to avoid any unfortunate collateral damage. Russia fails to clear the airspace, Israel proceeds with the operation anyway and ends up getting in the way of Syrian antiaircraft fire…which blows up a Russian patrol aircraft, killing all on board.
Normally I find Israel to be obnoxiously obnoxious, but every now and then I am reminded that they are obnoxious, but not cowardly. I can respect that. I reckon Russia ignored the warning and kept its aircraft in place on purpose, hoping Israel would delay/cancel the airstrike to avoid endangering the Russian plane. Israel, the nasty ass honey badger that they are, failed to care and allowed Russia to suffer the responsibility for its own belligerence. But maybe I’m not understanding what happened?