I suspect he was not attacking the senator but covering his ass because he only turned over the recordings that would be bad for the senators case.
I don't follow. How is hiding recordings that would exonerate the senator different from attacking the senator?
The withheld recordings might just have led the jury to distrust witnesses. Or, might have implicated other people besides. Doesn't mean the pol wasn't a crook. Or that the agent wasn't. There is often more than enough blame to go around, but prosecutors like things to look simple.
An investigation is not an attack. Are Senators above the law?
We aren’t talking about an investigation. We’re talking about an FBI agent intentionally hiding and destroying evidence. Exculpatory evidence.