A federal prosecutor thought she might have caught Cliff Sloan in a lie Tuesday—and that she had the proof in hand.

U.S. District Judge Amy Berman Jackson of the District of Columbia had warned Greg Craig several days earlier to not interact with his former law firm colleagues as he stood trial in Washington federal court on charges that he misled the Justice Department about his work for Ukraine while he was a partner at Skadden, Arps, Slate, Meagher & Flom. The judge's admonition underscored an awkward element of Craig's trial: His friends and former colleagues have been called to testify against him.

Among those friends and colleagues was Sloan, a former Skadden partner whom prosecutors originally summoned to the stand last week to testify about the Ukraine project now at the center of Craig's criminal trial. On Tuesday, Sloan returned to the stand as a defense witness, setting the stage for a tense cross-examination in which prosecutor Molly Gaston briefly appeared to question not only Sloan's truthfulness, but also whether Craig had defied Jackson's instruction to avoid interactions with his Skadden colleagues.

In his testimony Tuesday, Sloan described how Craig rebuffed efforts by the Ukrainian government to make changes to the report Skadden prepared in 2012 on the widely criticized prosecution of the country's former prime minister, Yulia Tymoshenko. Prosecutors have alleged that Craig, a former Obama White House counsel, misled the Justice Department about his role in the public release of the report to avoid registering as a foreign agent of Ukraine. Sloan's testimony appeared to bolster Craig's argument that the Tymoshenko report was independent and that he did not view himself as acting as a foreign agent of Ukraine.

Craig, who is expected to take the stand in his own defense Wednesday, has denied deceiving the Justice Department about his Ukraine work and argued he faced no obligation to report his activities under the Foreign Agents Registration Act, an 80-year-old law requiring the disclosure of foreign influence in the U.S.

At the end of her cross-examination Tuesday, Gaston made clear that Sloan was more than just a former colleague of Craig.

Cliff Sloan of Skadden (2009) Photo by Diego M. Radzinschi/ALM

"And finally, Mr. Sloan, you're friends with Mr. Craig, aren't you?" she asked.

"Yes," Sloan replied.

"You're close friends with Mr. Craig."

"Yes."

Gaston then asked whether Sloan had spoken with Craig after his testimony last week.

"With the defendant? No," Sloan answered.

"Did you leave the courthouse last week with Mr. Craig?" Gaston asked.

"No," Sloan said.

"You didn't?" Gaston asked.

"No," Sloan said.

Struck by the response, Gaston picked up a piece of paper and approached the bench, apparently believing she had photographic evidence of the longtime friends leaving court together Aug. 23. At the bench, a defense lawyer for Craig recognized the photograph from press coverage of the trial and said it had been taken a few years ago, when Craig and Sloan represented Gen. James "Hoss" Cartwright. The retired general pleaded guilty in 2016 to lying to the FBI in a leak investigation, and was later pardoned by President Barack Obama weeks before the retired general was to be sentenced.

"Then, I just made a big mistake," Gaston said, according to a transcript of the private discussion at the bench. Gaston then withdrew her question.

But Craig's defense team was not satisfied.

As jurors took their afternoon break, Craig's lead defense lawyer, Zuckerman Spaeder partner William Taylor, said some jurors might have caught a glimpse of the photograph. His concern gave rise to a debate over whether the paper in Gaston's hand was folded or rolled up—visible or not to the jurors.

"When she walked by the jury box," Taylor said, "the jury could see she had a photograph in her hand."

Prosecutor Fernando Campoamor-Sanchez said it was his "distinct recollection" that the paper in Gaston's hand was folded. "It was a photograph," he said, "but it was folded."

When the jurors returned to their seats, Jackson instructed them that there was "no evidence in the record" that Sloan spoke with Craig or exited the courthouse with him following his testimony Aug. 23.

"But there's also no suggestion or inference that you should draw that anyone did anything improper in asking to withdraw the question," the judge said. "The question was asked, it was answered 'no,' and that's what the evidence is."

Tuesday's tense courtroom exchange came against the backdrop of an admonition Jackson delivered two weeks earlier in the trial. On Aug. 16, Taylor disclosed to the judge that Craig had greeted Skadden partner Michael Loucks outside the courthouse the previous evening after his former colleague testified for prosecutors. Loucks, a former acting U.S. attorney in Massachusetts who worked on the Tymoshenko report, had yet to be cross-examined when Craig approached him outside the courthouse.

"Mr. Craig, this witness was in the middle of his testimony. He's still on the witness stand. He's not to be interacted with, nor are other witnesses in the case to be interacted with," Jackson said.

In addition to Loucks and Sloan, prosecutors called Craig's former secretary and Skadden's general counsel, Lawrence Spiegel, along with nearly a half dozen other witnesses with ties to the firm.

After Sloan's testimony Tuesday, Craig's defense team summoned four character witnesses, including Williams & Connolly partner Brendan Sullivan, a longtime leader of the firm. On the witness stand, Sullivan was asked whether he had an opinion about Craig's integrity.

"My opinion is that his integrity is beyond reproach," Sullivan replied.

In the cross-examination, Campoamor-Sanchez confirmed that Sullivan has not been attending the trial, in which prosecutors have presented evidence of Craig more closely involved in the public release of the Tymoshenko report than he led the Justice Department to believe.

Prosecutors have also highlighted the role Paul Manafort, the longtime political consultant, played in arranging for Skadden to take on the review of Tymoshenko's case in 2012, years before he became chairman of the Trump campaign.

Sullivan on Tuesday confirmed that he has not attended the trial or absorbed the prosecution's evidence.

"That is correct," Sullivan responded to the prosecutor. "'I'm a character witness."