Even more unsettling were his comments that he believes it could still be Russian disinformation.
"That letter was used in the debate, I haven't asked you this but do you have regrets about that now looking back, knowing what you know now?" Baier asked.
Panetta explained that he was "extremely concerned about Russian interference" in the run up to the 2020 Presidential Election between then-former-Vice President Joe Biden and then-President Donald Trump.
He claimed that intelligence agencies discovered that "Russia had continued to push disinformation across the board."
He said that he wanted to "alert the public" about the "disinformation efforts" to influence the election.
"And frankly, I haven't seen any evidence from any intelligence agency that that was not the case," Panetta said.
"You don't think that it was real?" Baier asked.
"I think that disinformation is involved here. I think Russian disinformation is part of what we're seeing everywhere," Panetta responded.
"I don't trust the Russians, and that's exactly why I was concerned that the public not trust the Russians either."
And finally, Baier asked if Panetta had any regrets over how he handled the story.
"No, I don't have any regrets about not trusting the Russians," Panetta said.