Former National Security Advisor Michael Flynn has been notably quiet after his resignation — but maybe he hasn’t been silent to everyone.

Some analysts, including national security expert Juliette Kayyem, say he may be cooperating with the FBI, a noteworthy development given his failure to disclose his contact with the Russian ambassador to Vice President Pence earlier this year.

“He’s been quiet, no one has seen him, he hasn’t been on-air defending himself,” said Kayyem on Boston Public Radio today. “Looking at Michael Flynn, his vulnerabilities, the fact that he had been fired, the fact that he likely knows something and the fact that he had been quiet ... would suggest to any lawyer that knows how these cases unfold, like myself, that this was the guy who was going to talk.”

Kayyem said there are multiple signs that point to Flynn cooperating with the intelligence community, one being that working with the FBI would allow him some protection from harsh punishment.

“He’s unemployable now, he’s the subject of several investigations, and if you’re Mike Flynn, you’re thinking, ‘What’s my way out of this?’” she said.

Kayyem also pointed out how Trump’s behavior supports the possibility that Flynn is considering talking to the FBI. She said Flynn has admitted that Trump still texts him, and Trump’s framing of Flynn’s dismissal as “a little bit of a media lynch mob” may indicate the president’s unease.

“That is what people do who are worried about the person who may flip,” she said.

Kayyem said predicting Trump’s next steps in the wake of Flynn’s possible cooperation might be difficult, but there’s one option that’s bound to be controversial: the presidential pardon.

“If [Flynn] does start talking, I think the next thing we will have to start talking about seriously as a nation is the potential that Donald Trump will begin to pardon these people,” she said. “If he begins to get worried that Flynn’s going to turn on him, he might preemptively pardon Flynn.”

Kayyem explained how presidents can preemptively pardon people for crimes or investigations, though there are legal provisions that could still require Flynn to testify.

“But still, pardoning him would mean he wouldn’t go to jail for potential crimes against our democratic system,” she said.

Kayyem cautioned listeners that despite the likely uproar that would follow a pardon of Flynn, a bold move from the president is not out of the question.

“Each time he does something in which you think, ‘That is inconceivable,’ the only explanation becomes [that] something illegal was done,” she said. “If Trump did something illegal, he has no choice.”

Juliette Kayyem is the founder of Kayyem Solutions, host of the SCIF podcast and a contributor to WGBH and CNN. To hear her interview in its entirety, click on the audio player above.