As a federal prosecutor, I heard dozens of defense attorneys criticize the use of accomplice testimony in criminal trials. The arguments are familiar—unseemly witnesses lie to curry favor with unscrupulous prosecutors motivated by a desire for conviction. They suggest to juries that these “snitches” are the real criminals in court, not the wrongly accused defendants sitting next to them at counsel table.

I recalled those arguments when I listened to President Donald Trump attack the use of “flippers” during an interview with Fox News after his former attorney Michael Cohen reached a plea agreement with federal prosecutors in New York. Trump suggested Cohen made up stories about him to obtain leniency from prosecutors. He went so far as to suggest that the practice of using accomplice testimony should be outlawed. And in the interview he also praised his former campaign manager Paul Manafort for refusing to cooperate with the Justice Department at the time.

Now that Manafort has changed his mind—Trump’s former campaign manager reached a plea agreement with the Office of Special Counsel, announced on Friday—the president will probably continue to bash criminal defendants who cooperate with the federal government. Although it is not yet clear what information Manafort will provide the special counsel, I expect a barrage of critical presidential tweets accusing Manafort of telling lies in the face of the undue pressure from an overzealous prosecutor.