Assignment of blame is not the objective.....finding an effective solution to the problems is the exact goal.
Did we rely on advanced technology, caste off proven techniques in the process, and by doing so....set ourselves up for failure?
As you correctly note JimL....the investigation begs questions whose answers are very important if they can be determined.
Every time we open up something as complex as a Gearbox....or dissasemble an aircraft's components to "inspect"....do we not introduce the possibility of contamination that can lead to failures shortly after the "satisfactory" inspection of the component?
Where do we draw the line between "inspecting" and "monitoring" to ensure a component remains "safe and serviceable" until TBO?