If we deny the Crown Office all of the evidence available then we deny them the ability to do their job properly. Is that what is wanted?
Bollox. The first and most critical issue here is to find the true cause of the crash. Basta, finito. Then, & only then, when the full facts are known should someone, with another agenda, come in and see if criminal prosecutions are in order.
I think, please correct me, that in France it is often the case where the gendarmerie take over an investigation ahead of the local AAIB. It has been seen that this delays, significantly, the finding of the true cause. This has to be the heart and focus of the investigation; not seeing if someone needs their wrist slapped. All too often we have heard 'pilot error' as the cause, when those of us inside the profession, and at the sharp end, know full well that there were other dark forces at work that were too embarrassing to publish. Keep the bluebottles out of it until the EXPERTS have been in first. That is the way the police do it themselves. Keep the plods out until the forensic white clad jumpsuit brigade have been in first with their toys.
Why two sets of rules. We have our own experts; let them do their job.