I think anyone connected with safety or mishap investigations needs to rethink why we do investigations, rather than blindly accepting the folk wisdom about investigation purposes. I suggest that purposes like "to prevent recurrence!" or "find the cause or probable cause or root causes" or affix blame or find out what happened and why or find lessons learned or settle claims miss the ultimate purpose, and misdirect investigation practices.
I'd offer this simple candidate: TO CHANGE BEHAVIORS. The reason for investigating an occurrence is to find, understand and report the behaviors that produced an unwanted occurrence, and their context, in a way that others engaged in similar behaviors can learn about them and apply that information to their future activities.
I would argue that this purpose would change how investigators do investigations and what they produce, by focusing their inquiries on what people, objects or energies did during mishaps, and why they did that. I would argue further that this would improve future investigation efficiency, efficacy and value. I would also argue that this would produce better predictive understanding of mishap phenomena if it were applied to present system safety analysis practices.
Anyone want to defend the status quo?