Classic compromised pick. Hire a guy you know you have something on, he plays ball, everyone is good. Called before congress... well we pull the trigger if he doesnt play the game. CIA 101
My understanding is that the House can still compel him to appear and,if they grant him immunity,they can *compel* him to testify.You can't take the 5th in a situation like that if you have immunity.
None of this adds up, read the story. The FBI “mistook” a Petraeus email for a reference to corruption. Using that as a ploy, they proceeded to monitor his affair and get every salacious detail, some of which they are leaking to the press.
This was done to get him when they wanted to get him.
It’s going to hit a “CIA Wall”, and go nowhere substantive.