You win the prize on that one. If he was involved the FBI should never have cut a deal with him. They should have just busted them both and let them turn on one another. Imo King was most likely Blottenberger's dealer. Blottenberger was the addict. The crime the FBI was after was bank robbery, not drugs. So they turned the dealer to informant so they could bust his customer who was robbing banks. Drugs weren't the FBI's concern here. That's for the DEA.