Former FBI Director James Comey's much-anticipated testimony before Congress Thursday offered a buffet of legal details for attorneys.

Comey testified before the Senate Intelligence Committee in a rare open hearing on Russia's interference in the U.S. election, possible collusion by the Trump campaign in that interference, and Comey's firing by President Donald Trump in early May. As senators took turns grilling Comey during the nearly three-hour hearing, he revealed several key details about interactions between himself and Trump, and his personal thoughts on what had transpired.

For lawyers watching the hearing, which was aired live on TV and streamed online, several key moments may stand out:

A Law Professor Leaked

Perhaps one of the most stunning moments from the hearing was Comey's admission that he orchestrated the leak of a memo he wrote detailing a meeting with the president, and that a Columbia Law School professor helped him do it.

On the morning of May 12, after he fired the FBI director, Trump tweeted that Comey “better hope that there are no 'tapes' of our conversations.” That tweet, Comey said in the hearing, prompted him to leak one memo he wrote after the president seemingly urged him to drop the FBI's investigation into Trump's former national security adviser, Michael Flynn, on Feb. 14.

Comey testified that if there were tapes of the conversation, he wanted to get his memo out into the “public square,” because any tapes would corroborate the memo. He later added he thought “it might prompt the appointment of a special counsel” for the Russia investigation.

But Comey didn't want to give the memo to the press directly because, at the time, reporters were parked at the end of his driveway and he was worried doing so would be like “feeding seagulls at the beach.” Instead, asked a “close friend who is a professor at Columbia Law School” to leak the memo to reporters.

That close friend, various news outlets confirmed Thursday, is Daniel Richman, a former federal prosecutor who teaches federal criminal law and evidence. According to his school biography, Richman was an adviser to Comey when he was at the FBI and has worked as a U.S. Department of Justice consultant on criminal matters.

After the hearing, Trump's lawyer, Marc Kasowitz, accused Comey of lying about when he decided to leak the information. He said The New York Times quoted the memos before Trump's May 12 tweet.

Comey's Legal Writing Skills

Sen. James Risch, R-Idaho, started out his line of questioning with a compliment. The committee released Comey's written testimony Wednesday, giving ample time for lawmakers and the public to comb through it.

The seven-page document reads almost like a spy novel or legal thriller. It tells the tale of awkward silences and uncomfortable moments with the president, and incorporated phrases lifted straight from Comey's memos, some of which he ensured contained no classified information because he had a “gut feeling” it would be important to document the moments with Trump.

One aspect of the written testimony that struck Risch was Comey's superior legal writing skills. He said the writing was “clear” and “concise” and that Comey deserved to be complimented.

“I read it, and then I read it again, and all I could think was number one, how much I hated the class of legal writing when I was in law school, and you are the guy that probably got the A after reading this,” Risch said.

He also noted that Comey, in an effort to make the timeline of events and his thoughts clear, had put phrases from the memos in quotation marks in the written testimony. This, Risch said, ensured lawmakers “know exactly what happened and we're not getting some rendition of it that's in your mind.”

Can a Defendant Be Convicted for “Hope”?

Risch's laudatory tone didn't last long, as his questioning honed in on a detail from one of those memos that sparked speculation on whether the president obstructed justice.

In the memo following his February meeting with the president in the Oval Office, Comey wrote that after asking everyone to leave the room, Trump told him, “I hope you can see your way clear to letting this go, to letting Flynn go. He is good guy. I hope you can let this go.”

Comey said he took this as a direction from the president to drop the FBI's investigation on Flynn. Risch pushed Comey on that interpretation, asking him if he knew of any cases in which someone was charged with obstruction of justice because they “said or thought they hoped for an outcome.”

Comey said he didn't, but that the circumstances of the discussion made him uncomfortable.

“I mean, this is a president of the United States with me alone saying I hope this,” Comey told Risch. “I took it as, this is what he wants me to do. I didn't obey that, but that's the way I took it.”

The question of whether someone can be convicted of obstruction of justice for “hoping” lingered after the hearing. On Twitter, The New York Times' Adam Liptak, a lawyer himself, noted a case out of the Eighth Circuit in which the court upheld an increased punishment for obstruction of justice due partly to an “I hope” statement. Victoria Kwan, a creator of Scotusmap.com and a contributor to Scotusblog, then tweeted about a case out of the Fifth Circuit that showed an obstruction of justice conviction based on an “I'm just hoping” comment.