Under advisory sentencing guidelines, Flynn is facing between zero and six months in prison.
But the filing said that the agents were anxious that warning Flynn "might adversely affect the rapport". In his reply, Mueller says that the argument that Flynn was tricked or ambushed does not hold water, and should not be considered a mitigating factor in Flynn's sentencing.
"Even when circumstances later came to light that prompted extensive public debate about the investigation of Gen. Flynn, including revelations that certain FBI officials involved in the January 24 interview of Gen. Flynn were themselves being investigated for misconduct, Gen. Flynn did not back away from accepting responsibility for his actions", Flynn's lawyers wrote.
Flynn's attorneys had pulled from those documents in pointing out that unlike other defendants in the Russian Federation investigation, Flynn wasn't warned in advance that it was a crime to lie to the FBI.
"A sitting National Security Advisor, former head of an intelligence agency, retired lieutenant general, and 33-year veteran of the armed forces knows he should not lie to federal agents", the memo says.
JOHNSON: You know, the lawyers say he is taking responsibility for making a bad decision and breaking the law, but then they go on to cite a couple of very interesting paragraphs - the circumstances surrounding his January 27 interview with two Federal Bureau of Investigation agents in the White House. Then FBI agents, who already knew the answers because they'd read the transcript, rushed to the White House to ask questions about a perfectly legitimate phone call.
That order, in turn, followed a sentencing memo earlier this week by Flynn's lawyers in which they argued for leniency. And authorities say they'd be OK if he served little or no prison time.More news: Sterling crowned PL Player of the Month
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That footnote does not say exactly when the Mueller Special Counsel handed over these exculpatory documents detailing the scheme to entrap Flynn. Investigators have examined key episodes such as Trump's firing of former FBI Director James Comey and his fury over the recusal from the investigation of former Attorney General Jeff Sessions.
Flynn's lawyers have prepared a memo for the court ahead of Flynn's sentencing stating that former FBI Deputy Director Andrew McCabe recommended to Flynn that he not have a lawyer present during questioning by FBI agents. And it described Flynn as a dedicated and fearless officer, noting that while deployed in Grenada, he once dove off a 40-foot cliff and saved two servicemen who had been swept out to sea. "He has cooperated extensively with several Department of Justice investigations", and did so before his guilty plea, the lawyers said. We had heard last week from the special counsel that Flynn had met with them 19 times.
Flynn, however, agreed to be interviewed alone.
Flynn initially denied but eventually said that they had discussed sanctions and a United Nations resolution during the presidential transition.
The filing also makes clear that Flynn's lie - which, to be clear, he has pleaded guilty to - wasn't a mere slip-up in a casual interview.
Former federal prosecutor Joe diGenova blasted the federal government for what he called "one of the most disgraceful events in American criminal justice".
Trump brushed off a question about his associates' interactions with Russians before and during his presidential campaign as just "peanut stuff" during an interview with Reuters on Tuesday.