I didn't ask how much it would cost, I asked who would pay for such 'independence' - if it's government funded then the government and all its facets pulls the strings, look at the XX177 whitewash, neither the HSE or the police have been interested in really pointing the finger and M-B just rolled over.
The HSE are supposed to be independent, the police are supposed to be independent but they're both bankrolled ultimately by the government and where it's not in their interests to have the finger pointed at the MoD then 'independence' goes out the window where perhaps certain persons' reputation (and pension) are at stake, whether they be minister, VSO or in the commercial or security interest of certain companies.
Independence of the MoD is no guarantee of influence from afar - you will never have a completely independent regulator/investigator.
Unfortunately it'll never change or if it did it would be the result of a public outcry and that's not going to happen unless there's a catastrophic incident involving multiple members of the public - all of the accidents so far, sad and avoidable as they were, have not involved the public at large in that sense.