I do not see any way how your analysis should begin with, "who benefits?"
Well, so far we have given the Ukrainians MRE’s and CIA people. I think they’re looking for a bit more support.
Every analysis should begin with “Who benefits?” It is often the clearest path to the truth, as it frames the conflicting motives of the overt (obvious) and covert (hidden / agents provacateur) players. The evidence might point to an intentional act by either side, or to the unintended consequence by either, or to a third party. My first suspicion is that the separatists thought they were shooting at another Ukrainian military transport, especially since most civil aviation had been routed away from the area. Perhaps we’ll know one day, but perhaps we won’t.