In the past week, as Covington & Burling scrambled to ensure the entire case file of its former client Michael Flynn had been turned over to his new lawyer, the law firm bristled at what it considered an unreasonable request from the former Trump national security adviser.

On Monday, Covington said in a court filing that Flynn’s new lawyer, Sidney Powell, had called on the firm to go beyond the case file and conduct a more expansive search encompassing “every communication of any kind, including telephone records of every call, of every Covington employee, in which the Flynn case is mentioned.” It was a position “strikingly different from the well-recognized obligation of a law firm to turn over the client file to successor counsel,” the Covington lawyers said.