Comey is so smug in his answers to congress. So full of himself. He responds to questions about national security like people are asking him why he didn't take out the trash. "You know, I just forgot."
At one point Jim Jordan is asking him, "So why when you were having dinner with the President and the President brought up Michael Flynn you didn't tell him you had two agents just interview Flynn and you have reason to believe Flynn is a liar?" Comey's response is basically, "you know, I didn't feel the President needed to know because it was still an open investigation." Like he is the Trump's boss, and he will decide what Trump needs to know. And for Comey, the fact that the FBI suspected the National Security Advisor to POTUS of being someone of dishonest character was not something that Trump needed to know.
He also shows how much he loves to hide behind "classified" to escape questions. When Gowdy asks him a question pertaining to the Flynn conversation, Comey runs to the FBI lawyers to see if they will allow him to not answer under the "that's answer is classified" ruse. The lawyers give Comey the go ahead, and like the smug son of a bitch he is, he says to Gowdy, "Sorry, no luck. I can't answer that question"
Congress created and funds the FBI, which would imply they should have authority over the institution. But instead the FBI dictates to congress what they can and can't know. I understand there are matters of national security that can't be shared with the public at large, but there needs to be a mechanism that allows members of Congress to see classified material, so we don't have all these FBI, CIA, NSA guys telling them constantly, "No luck buddy. That's classified."