Back in the old days, when grand juries were not run by the state, this would not have been an issue. Indictment would have come regardless of what the cops thought.

At least Comey was honest about "what this is really about":

To be clear, this is not to suggest that in similar circumstances, a person who engaged in this activity would face no consequences. To the contrary, those individuals are often subject to security or administrative sanctions. But that is not what we are deciding now.

No, because the current government is always and everywhere immune to prosecution when it controls the justice system. That was decided long, long ago.