I find this thread fascinating. I’m astonished you’ve been able to find anything to seek redress for that hasn’t already been (a) condoned by senior management (in that no action has been taken) or (b) formally ruled as not constituting wrongdoing. That is, a precedent has been set.
No doubt it is slightly different in the Services but in the Civil Service the burden of proof is on the person seeking “redress” and that burden is very much higher than one would experience in the civil courts. For example, witnesses, written evidence etc. can simply be ignored by the officer hearing the case. In fact, he is under no obligation to interview witnesses in the first place, or read the evidence. I’ve only known one person to be successful. He took it all the way to the Cabinet Secretary, ignoring the “rule” that says PUS is the final arbiter. He is a very strong character, and had to be when, as you say, he discovered who is friends were. Yet, even though he won (in financial terms) no action was taken against the offenders, most of who were promptly promoted.
I’ve seen people get away with the usual things like fraud, bullying, harassment, lying in annual reports, maladministration (all quite common) but the one I always remember was falsifying inspection records on aircraft components (in order to get more bonus). The guy was told to pick another inspector next time, one who wouldn’t spot the deceit! I got an earful for (a) refusing to stamp for the job (or catching him out, I was never sure) and (b) reporting him in accordance with the regs. I didn’t seek redress, I applied for a posting. (His dad was a gaffer, so I’d never win). He got promoted off the bench (which is one way of stopping him doing it again – rewarded with more pay). The fly guys at Leuchars thought I deserved a medal. (Would YOU want your crash switches going off at 2g?).