That said, there is a facepalm moment in each video when you realize the agency has no regulatory authority and can only make recommendations that may or may not translate into voluntary compliance actions.
I'm totally not in the field, so I have no idea how often OSHA/EPA follow up on USCSB recommendations, and if OSHA and EPA's remit are sufficient to be able to enforce/mandate the majority of USCSB recommendations.
For example in the video USCSB identifies that TPC had internally recommended and green-lit procedures for flushing out of use lines to prevent popcorn polymer formation, but did not actually implement the action.
I know in medical device land, this type of thing (say someone internally recognizes a risk to device safety in the manufacturing process, a mitigation is accepted and greenlit, but never actually implemented) would be subject to both quality audits (so by someone checking up on your ISO status), and potentially as part of FDA follow up audits. I don't know what the situation in this field would be like.
The idea being that they'll have purer incentives to get the truth? And maybe get better cooperation? I'm sensing the outline of how this arrangement is "powerful", but having trouble with the full picture and details. And per your sibling comment, it might still be good to have a formal process for enforcers to have a look at their results...
- people will be more willing to talk to investigators if they know that their evidence won't be used against them in court or used for a licence suspension
- you can grant non-regulatory investigators greater powers to compel testimony and documentary evidence, perhaps even if it's self-incriminating (I can't speak for the US but it's common here in Australia where we don't have a 5th Amendment entrenched guarantee), without running into as many ethical issues as when you give coercive information-gathering powers to regulators - you ban such compelled testimony from being used as evidence in court or in regulatory proceedings
- you don't need as high a standard of proof to make an investigatory finding as if you're taking punitive action against a specific individual
- the overall purpose of the investigation is aimed at systemic safety, rather than getting a successful prosecution
None of this prevents the regulators from running a parallel investigation with the aim of regulatory punishment - and indeed, two sets of independent eyes on complex scenarios is good too.
Assigning blame usually results in more arse-covering and indirection than disaster reduction. See also: NTSB.