Bart,
You are absolutely correct; "i t is best to await the detailed results of what ever the investigators and their determinations conclude."
It is clear the policy makers in the US State Department aren't willing to wait for an accurate determination. They are anxious to force Europeans into a cold war which will ultimately affect their economy and save Obama's face after Putin pulled him out of an embarrassing premature "red-line" in Syria.
Notice that lots of commercial airlines have been accidentally shot down by the USA, Russia, Israel etc. The consequences did not result in any significant pressure.
At the same time you will notice that the US doesn't produce its information that is supposed to support its claims. In fact Obama had to quickly say it had no proof that Russia or Rebels were responsible. If he would have insisted on that stance he would have to share the evidence the USA has and that evidence at the very least might incriminate the Ukranian forces perhaps a Rogue Nazi group financed by one of the crazy oligarchs in Ukraine.
Still, the American Press keeps whipping up anger by repeating the false accusations started by John Kerry and Obama.
Here is an article by a very reputable reporter - Robert Perry
http://consortiumnews.com/2014/08/03/flight-17-shoot-down-scenario-shifts/
While the USA can use air strikes to prevent a humanitarian disaster in Iraq where ISIS is attacking christians Russia has its hands tied in preventing the killing of civilians and systematic destruction of major cities in Eastern Ukraine. Actually the USA and NATO are encouraging Ukraine to get the job done even though they know there are war crimes being committed by using huge bombs in civilian areas.
It looks like the drum-beat of war can't be stopped.