Even if he 'knows' it's an undercover US department.
So, they would and should still throw the book at him.
He'd be secretly dealing in 'data', fake or not, and money related to his classified job. Not hard to see that's very illegal. He would be leaking info as well just talking to them. They might collate speech structure that links him to other non classified/leaked projects. Or know where he lives or work hours.