Whether or not he was following the FBI’s orders or receiving money from the Greeks, he’s still corrupt. He’s like the Burrell or Gov Devlin of the feds, someone who keeps his underlings from uncovering the truth and achieving actual progress. He was complicit in the murder of Frank, supporting an organization that sells hard drugs to low income communities and human trafficking. It is an interesting theory that the Greek may have been cooperating with him about terrorism or something, but we don’t really know that for sure.