100% of the reponsibility lies with Air New Zealand Limited, which was the employer of everyone involved (putting the Mac Centre issue to one side).
The debate is about the apportionment of blame between different groups of employees. If it's Crew/The Rest, I would be prepared to accept Sir Rochford Hughes' 10%/90%. Prospector might even be prepared to do the same - but I can't stomach 0%/100%, because as he said, the plane is still down there.
Here's a question: What would Jim Collins say?