In a filing last week before the appeals court, a lawyer for Judge Sullivan urged a three-judge panel not to short-circuit his review, saying he would not necessarily adopt the arguments put forward by Mr. Gleeson.
The spectacle of both the district and appeals courts simultaneously dealing with the same case is unusual, said Samuel Buell, a law professor at Duke University and a former federal prosecutor. Mr. Gleeson’s filing will not legally affect the appeals court panel’s decision on whether to end the case without further review, he said, but “it will contribute to the overall atmosphere with regard to the propriety of the government’s motion to dismiss.”
To justify Mr. Barr’s decision to drop the case, the Justice Department has argued that Mr. Flynn’s lies were not “material” to any legitimate investigation — rejecting the department’s own previous position that his lies were relevant to the counterintelligence inquiry into the scope of Russia’s covert operation to tilt the 2016 election in Mr. Trump’s favor and the nature of links to Trump campaign associates.
Mr. Gleeson, who had co-written an Op-Ed article calling into question the legitimacy of Mr. Barr’s intervention before Judge Sullivan appointed him, offered a blistering critique of that rationale.
“Pursuant to an active investigation into whether President Trump’s campaign officials coordinated activities with the government of Russia, one of those officials lied to the F.B.I. about coordinating activities with the government of Russia,” Mr. Gleeson wrote. “It is hard to conceive of a more material false statement than this one.”
Marching through other issues raised by Mr. Flynn’s defenders and embraced by the Justice Department, he portrayed the arguments as “absurd,” “legally unsound,” “misdirection,” “preposterous” and “empty.” He said the department’s request was both “riddled with inexplicable and elementary errors of law and fact” and departed from its position in other cases — all evidence, he said, that its rationale for dropping the case was just a pretext.
Mr. Flynn had pleaded guilty to lying to the F.B.I. in December 2017 about his conversations with the Russian ambassador the previous month, during the transition period after Mr. Trump won the 2016 election. The Obama administration was taking actions to punish Russia for its interference in the American democratic process, including imposing sanctions on Russian intelligence agencies and expelling Russian officials from the United States, and Mr. Flynn and the Russian ambassador, Sergey I. Kislyak, discussed the moves.