(NewsNation) — A lawyer for Steve Bannon says his team has a “bulletproof appeal” after his client was convicted of contempt of Congress last week.

Bannon, a longtime ally of and adviser to former President Donald Trump, was convicted Friday of contempt charges after refusing to comply with a subpoena from the House committee investigating the Jan. 6, 2021 riots at the U.S. Capitol. Bannon said he couldn’t testify because of executive privilege claims by Trump, even though Bannon never officially worked in the White House.

Joining NewsNation’s “Dan Abrams Live” on Monday, attorney David Schoen took aim at one of Bannon’s previous lawyers and also said the judge in the case was incorrect to rule that some elements of Bannon’s planned defense weren’t relevant and couldn’t be used in court.

“The jury wasn’t permitted to hear anything about Mr. Bannon’s reasons for not complying,” Schoen said.

Before the trial began, U.S. District Judge Carl Nichols said Bannon could not claim he believed he was covered by executive privilege, which allows presidents to withhold confidential information from the courts and the legislative branch, or that he was acting on the advice of his lawyers.

Bannon’s lawyers tried to argue during the trial that he didn’t refuse to cooperate and that the dates “were in flux.” They pointed to the fact that Bannon had reversed course shortly before the trial kicked off — after Trump waived his objection — and had offered to testify before the committee.

Watch the discussion in the video above.

The Associated Press contributed to this report.