Reading what bob, Andi and Grahame have posted. It strikes me that the full truth of what took place prior to the raid, during the raid and in its immediate aftermath, have not yet been uncovered or volunteered. It is therefore not possible to nail down the exact motives for any kind of 'cover our backs' re-staging. The only thing left is to speculate from what is known or strongly suspected.
But if there was a re-staging of any kind involved, which then implemented a deception that got past a coroners inquest, surely people can see that this is extremely serious.
RWB was going higher and higher up the chain. Where do you think he would have stopped if ACC Simpson had f***d him off? Since this very ACC is alleged to be at the top of those in the know at the time this was happening, it's not unfeasible that he was indeed left with a very stark choice.