I was the senior member of a Mishap Board for a single A-4 accident and did the Judge Advocate General (JAG) investigation on an F-14 midair. The Navy's Mishap Board exists to determine causal factors and what can be done to prevent future mishaps. All statements to the Mishap Board are immune from legal action, which results in more honest statements and a better assessment of the mishap. However, JAG investigation statements can lead to legal culpability and everyone making a statement is apprised of that before making their statement. I'm not aware of instances where the JAG investigation actually resulted to criminal liability, but I do know that the privileged nature of the Mishap Board is an effective way to get the unvarnished truth.
Regards,
Gus