Former US Attorney Preet Bharara. REUTERS/Brendan McDermid

Preet Bharara, the former US attorney for the Southern District of New York, called House Speaker Paul Ryan's defense of President Donald Trump on Thursday "silly," and he offered a counterpoint to Ryan's argument.

During former FBI Director James Comey's hearing before the Senate Intelligence Committee on Thursday, Ryan held a press conference in which he attributed Trump's apparent attempts to persuade Comey to drop the investigation into the president's former national security adviser, Michael Flynn, to his inexperience in politics.

"Of course there needs to be a degree of independence between [the Department of Justice], FBI, and the White House, but a line of communication needs to be established," Ryan said. "The president is new at this, he's new to government, so he's not steeped in the long-running protocols that's established between DOJ, FBI, and White Houses. He's just new to this."

Bharara, whom Trump fired in March, responded to Ryan's remarks in a social-media post Thursday night: "Silly. DJT knew protocol well enough to attack, rally after campaign rally, the breach of 'protocol' in Clinton's tarmac meeting with Lynch."

Bharara was referring to the occasion in which former President Bill Clinton met with then-Attorney General Loretta Lynch on a tarmac in Arizona last summer during the presidential campaign, an event that drew outrage among Republicans — including Trump — because the Justice Department at the time was investigating Hillary Clinton's use of a private email server.

At the time, Trump said he was "flabbergasted" by the meeting, and he routinely brought it up during campaign events.

"It's a very serious thing," Trump said at the Western Conservative Summit in 2016. "To have a thing like that happen is so sad."

"If you think that he just happened to be at the airport ... he was talking about golf and grandchildren ... but if I talk about them for more than about nine or 10 seconds ... after that, what are you going to say?"