I suppose you are correct. I think the butchers have their fingers on the scales.
On your original question (I don’t practice in the criminal defense area) could it be that by showing the Grand Jury everything the defense will get all evidence if there are charges preferred? In other words, the defense will get a total heads up on all possible evidence. There would be no concealment, or Perry Mason moments.
Of course the federal busybodies are not investigating state law violations.
The defense ALWAYS gets all evidence pre-trial. Whenever anything new comes into the prosecutor’s possession, it is forwarded to defense counsel. Perry Mason moments are no longer allowed (drat it all!)
It might be that the grand jury is getting everything fresh so that when they no bill him, they will have plenty of evidence to back up their decision.