A New York federal trial judge on Tuesday partially unsealed a ruling that provided the court’s basis for stopping Sidley Austin partner James Cole, a former Obama-era Justice Department leader, from serving as a defender for the Chinese telecommunications giant Huawei in a U.S. criminal case.

U.S. District Judge Ann Donnelly’s order in December disqualifying Cole from participating in the case did not explain her reasoning. Much of the dispute involving Cole’s participation has unfolded under seal in the U.S. District Court for the Eastern District of New York. Donnelly’s unsealed order only disqualified Cole, based on his prior work at the Justice Department, and not Sidley Austin itself.