Swiss cheese? I'm seeing mainly holes and not much cheese. And an awkward transition from a military/marine mindset to a civilian commercial one. Look at the struggle that experienced, offshore pilots posting here have trying to understand what t'hell the crew was doing as a supposed "SOP" procedure.
Systemic, crew is not at fault. Tough day for management, that were not able to foresee the flaws in their operational system - the responsibility of both the SMS system to successfully risk assess and operations to provide operational expertise in a predictive way, not after the fact like the AAIU has to do now. Other operators fly SAR in that area, I wonder if they shared the same SOPs or if their different management expertise was ahead of the game.