I believe it's possible to have more than 100% blame for a situation.
Those that shot-down a civiian airliner deserve 100% of the blame for shooting it down. That's a given.
Those that provided weapons without providing proper training deserve some blame.
Those that gave orders in the heirarchy to the crew that fired the missile deserve blame, even if they weren't actively involved in the choice to engage the target.
Those that chose to fly through that region also deserve some blame. Not as much blame, but some.
And honestly, I don't have a problem with the concept of blaming, at least to a small extent, the victim. That doesn't mean that one should shame the victim, but from situations as insignificant as not maintaining situational awareness when walking through a rough neighborhood and being mugged to as large as flying through a warzone all have a kernel of blame attributable to the victim, in that the victim's choices assisted in being victimized. The world is a harsh place, and while the perpetrators of violence are 100% responsible, there's still more blame to assign to some of those that fail to take basic steps to protect themselves or those in their charge.