Let me ask you a serious question.
If the feds wanted to get you do you think they could? I mean, do you think you could survive an FBI "interview" without being caught in a lie? Could anyone? And if they said you lied and you didn't, how exactly would you go about proving it? Ask for the tapes?
Any agency can do this. Without a tape you contest it at trial. The FBI usually doesn't need those notes to nail you though. As I get to below, this is an agency that tends to do their homework.
They are starting to tape confrontational interviews, but that really isn't the problem. The problem is that the penalties in the federal system are just absurdly harsh, so innocence is besides the point because rolling the dice at trial is insane. But that tactic isn't on the FBI as much as the AG and individual AUSAs, and ultimately Congress.
I'll fully agree that there is mind-bending potential for abuse in the federal system far in excess of what is believable in certain aspects of the law. No question.
That said, of all the police agencies I've ever had dealings with, my confidence in the FBI is so far above every other branch I've dealt with that I'm not sure I could name a second. They aren't perfect, mind you, they have the same problems with any other agency ran by humans. I don't do federal stuff as a rule, in part because it is no fun because they rarely screw anything up making it no fun for me.
So, even though I literally make most of my living being critical of law enforcement, I don't find these texts anywhere near severe enough to discredit this agency as a whole, especially before we find out about how they handle how the bias effected the investigation. It isn't good, but the people screaming about a coup are out of their fucking minds, or are using it as a tactic because the FBI has the goods on them and this is what is left.
This is a political ploy to disrupt an investigation, nothing more. These otherwise law and order fanatic assholes are willing to try to flush a respectable agency down the drain by making wild claims in the press rather than contest their findings within the system like they expect the little people to do.