As part of my job - alas no longer connected with aviation - I instruct and advise senior personnel in petrochemical companies on different RCA (Root Cause Analysis) techniques that can be used to investigate incidents and eliminate repetition.
I know the world is not perfect but it is essential to get past the WHAT happened, the WHO did it or was responsible and get to the WHY it happened. At this point you may stand a chance of fixing what went wrong. That after all should be the aim of the investigation.
Some wise people at ICAO I think may have recognised this when they wrote those paragraphs.
I like the concept in Oz where the investigation by the accident investigators is separate from any legal action. No-one will be fully honest with the investigators if they believe that what they say can be passed to the local prosecution service and used against them. Hence the necessary information needed to prevent recurrence will be - at best - 'tarnished'.
I have no experience of the FAA techniques but the worst examples by far I have seen of air accident investigation are those performed by Boards of Inquiry in the RAF. By and large they arrive at - an often incomplete - WHO is responsible rather than a full WHY. In my time the Board could not even recommend corrective actions. Take a look at the Nimrod and Chinook threads in the mil forum as evidence.
Please allow me a comment on this statement:
99% of accidents can be prevented
My belief is that this statement accepts that some accidents are inevitable. If you accept this you are already on the wrong side of the drag curve.
I would prefer that the industry accept something more along these lines:
ALL accidents are preventable
Cheers
lars