There will never be a "proof" regarding this episode. There may be future revelations, but it is unlikely that it will significantly affect the credibility of the cover story. The credibility is already extremely limited.
I would guess that a policy decision came down from Clinton that the plane blew up accidently. Anyone who made a claim inconsistent with that was pressured to give in. Their opportunity to object has passed.
The picture of the x-ray taken of Ron Brown's head clearly shows a pattern of debris in his skull, with no reasonable explanation for how it got there. The cover story that the x-ray cassette was defective can be challenged, but not conclusively discounted. ( What an incredible coincidence that all 33 particles on the x-ray cassette just happen to fall within the outline of Brown's skull.) The follow-up x-ray that was supposedly taken is missing.
Whatever was in Ron Brown's skull is still there if the information that Brown was not cremated is correct. I doubt that anyone will ever be allowed to exhume him and identify the debris. There will never be "proof" that Ron Brown did not die as the official determination states.
That the FBI, the CIA, the BATFE and other government agencies lie is a fact which few will contest. The possible scenarios involving such lies and coverups create a smooth continuum from illegal acts involving just a single person to cover-ups like TWA-800. It is impossible for an intelligent person to discern any point at which the suggestion of misconduct becomes too implausible.
Another aspect of cover-ups is that the "conspiracy theorists" must be discredited. The idea that our navy was involved in an exercise which went bad might be an example of a story floated to discredit the missile theory.
Many people who might believe that a cover-up could occur may not be sympathetic to those who would claim that our own navy would fail to reveal the truth. Such people will not want to be associated with an attack on the credibility of the navy and they will then choose not to be associated with anyone who doubts the official "explanation".
Who would believe that Pellicano would hire people to tap phone lines and plant intimidating items in a person's car? Now we know that he did and that he was in possession of explosives. Who now doubts that someone in power could hire Pellicano or someone like him to plant a bomb?
Were was Pellicano when the Earth Firsters supposedly blew themselves up? There were complaints that the investigation targetted the environmentalists to the exclusion of everyone else.
Where else do we see the investigators targetting someone to the apparent exclusion of everyone else? How about Richard Jewell? Gee, another explosion. How convenient. Isn't Rudolph floated as the bomber now? I thought he was targetting abortionists? What is the connection with an Olympic site? None that I know of.
That our Supreme Court is out of control is obvious. Their decision on the Foster photos will set a powerful precedent either for or against government withholding of evidence. Much more than just the fate of Vince Foster rides on this case.