I am making a value judgement: the western authorities don't have a vested interested in covering up facts, the entities that "reportedly" shot down a civilian aircraft do have a vested interest in covering up facts. If you want to reserve judgement until all the results are released that is fine, but there will be some data that will not be released to the general public as the sources will be classified.
And that's a major part of the problem; being forced to take the word, to any extent, of people who have lied to the world in the past. I beg to differ about Western vested interests however. The West clearly wants Russian influence out of Ukraine, and if this situation helps to achieve that, then I think it's possible, likely even, that they would be economic with the truth.