It is the kind of fine print to which lawyers devote many billable hours crafting and reviewing. Rick Gates’s plea deal with special counsel Robert Mueller includes this line: “The defendant agrees not to reveal his cooperation, or any information derived therefrom, to any third party without prior consent of the Office.” The language of Paul Manafort’s cooperation deal is almost identical—with the exception of that sentence about disclosing information to third parties. “The absence of that gag order is not an oversight,” says Katya Jestin, a former federal prosecutor. “This could be part of a larger strategic play by Mueller. Which gives this a John le Carré aspect.”

On Monday, Mueller went to court to take the rare step of invalidating a plea deal, accusing Manafort of lying after agreeing to cooperate with the government; Manafort maintains that he told the special counsel the truth. The stunning collapse of Manafort’s deal raises a bigger and more intriguing question: who created that loophole about talking to third parties, and is it part of a sophisticated game Mueller is playing? Or did President Donald Trump just blunder into incriminating himself?

Manafort’s lead lawyer, Kevin Downing, reportedly walked through the plea deal’s open door straight to the White House, sharing information about the inner workings of Mueller’s investigation for Trump, a subject of that investigation. Downing appears to have told Rudy Giuliani that Mueller’s team was highly interested in the circumstances of the June 9, 2016, meeting attended by Manafort, Jared Kushner, and Donald Trump Jr., the one where Russian lawyer Natalia Veselnitskaya was supposed to reveal “dirt” on Hillary Clinton. “Mueller wants to know about the Trump Tower meeting? Duh!” says Solomon Wisenberg, who was one of Ken Starr’s lead investigators in the Bill Clinton-Monica Lewinsky case. “That’s not exactly a revelation. But here’s the risk. If a prosecutor says to a cooperating witness, ‘Look, we know this happened, because of A, B, C, and D,’ and the witness is relaying that supporting evidence to someone else—if I was on Mueller’s team and I found out that was happening, I’d be very pissed.”

Unless that chain of events was by design. Mueller and his team are known for being straight shooters and as sticklers for legal ethics. The greatest likelihood is that the special counsel agreed to leave out the prohibition on talking to third parties because Manafort had little rational incentive for doing so—and could be punished for bad behavior. Indeed, Mueller is now asking the court to sentence Manafort immediately, and will probably ask for a longer prison term. Yet Mueller’s team has always thought strategically about how to deal with Trump—for instance, farming out portions of the investigation to other jurisdictions who couldn’t be shut down by the president. Did they agree to omit the third-party clause as a way to test Manafort and Trump?

The timing of Mueller’s split with Manafort is curious: he announced it just days after receiving Trump’s written answers to the special counsel’s questions. The tantalizing possibility is that Trump, basing his answers on what he was hearing from Manafort, lied in those written answers and has now stumbled into strengthening the obstruction of justice case against him. “Mueller built the plea agreement to permit Kevin Downing to continue to share information with Rudy Giuliani,” says Marcy Wheeler, a national security expert who blogs under the name Emptywheel. “So in the eventuality Manafort lied and Mueller didn’t tell them what evidence they had that he was lying, then that would in a sense be negative reinforcement for Trump. He would think that he was going to get away with it, just like Manafort was.”