jcjeant, it's simplest to rule out more than one "failure" per incident. Look for a failure (in reliability speak terms) that could cause the given effect. There might be say 20 such failures. If nothing fits start looking for combinations of failures that could lead to the overall results. That's maybe 400 combinations to consider. Three such failures is 8000 combinations of those 20 items, alone, to consider. And once you consider one of the 20 plus something else you may discover something else might be 5 or it might be 50 different failures could lead to the results.
Considering "partly failed" becomes a nightmare.
And I suspect BEA is being just a whole lot more methodical working through the various trees and figuring out what external influences the plane experienced than we are.
So I figure it's not time to worry yet about conspiracies or pinning blame where it does not belong. And I note you're not working to go beyond "failure" to find "cause" which is required before you can assign "blame." You're before the cart the horse putting. (or something.) It does SEEM like you're very anxious to get to the blame part. OUR analysis here isn't anywhere near that, yet.
For people who lost a loved one it's quite natural to want to find a target at which they can lash out and vent their fury. Premature action leading to selection of the wrong victim for that fury can be most tragic. (This is often how feuds and wars begin.)