Let’s make something clear.
Anyone who says that either Ukraine, Russia or the Russian backed rebels in Ukraine were out to shoot down a passenger plane at this time (Korean Airlines from the 80’s not withstanding) is out of their minds.
Anyone with any knowledge of how war works know what has happened.
One side (almost certainly the Russian Backed Ukrainian rebels) thought they had targeted an enemy plane and shot it down.
It is unlikely to have been an accidental shootdown by Ukraine proper because they would have info on the flight path and any corrections.
The normal and proper thing to do is an apology, correctly calling this an accident of war and promising both eventual restitution but also reiterating that the skies above Ukraine are in a war zone and people should act accordingly.
The rebels will not admit this because it is bad PR for their Russian backers and for that same reason and because he has been feeding his own people false propaganda concerning Ukraine Russia will not allow this to be used.
The Ukrainian government will call this a terrorist attack in order to get international support. While they have an excellent case that the entire war is a Russian creation it would be inaccurate to call the downing of the flight terror.
Meanwhile this put America in an odd position.
The US position of saying nice things but doing nothing has actually worked out quite well, by not getting involved directly it has not put Russia in the position where they have to intervene in order to save face, while at the same time it has allowed Ukraine who decided not to worry about what the west is doing to fight the war on their own terms beating the rebels badly. They are well on their way to winning the war.
The US has to be clever here, the best thing to do is to push the actual truth. (Manslaughter not murder) and to push the idea of both Russia & them staying out or at most suggesting that Russia could, as a proxy for the rebels pay any indemnity to the families of the dead.
If we decide to grandstand if we make grandiose proclamation we might actually make things worse.
If however this administration uses sober level headed intelligent diplomacy we’ll be fine.