NBC News Chairman Andrew Lack sent employees a detailed memo and an 11-page analysis Monday spelling out why the news organization felt it could not air journalist Ronan Farrow’s 2017 investigation into harassment allegations against movie-mogul Harvey Weinstein, the latest rebuke by the Comcast-owned unit against accusations it passed on one of the hottest stories in recent years without obvious reason.

“We spent eight months pursuing the story but at the end of that time, NBC News – like many others before us – still did not have a single victim or witness willing to go on the record,” Lack said to staffers in the memo. Farrow disagreed with that standard, Lack said, and the two sides parted ways.

Release of the executive analysis, which includes transcripts of on-camera interviews between Farrow and others as well as a timeline of phone calls Harvey Weinstein and his attorneys made to various NBC News executives, is a remarkable display of evidence from a sector of the media that often does not provide much information on how it reports out stories. CNN, Fox News Channel and others have also in recent months been called out on how they report sensitive matters, and while the news organizations may offer comment, they typically do not bring to public view an accounting of how their product gets made. But the Lack memo also hints at the public pressure recently brought to bear on NBC News, which in 2016 was scooped by The Washington Post on another story related to sexual harassment, the existence of a tape from “Access Hollywood” — a show that is part of its parent, NBCUniversal – featuring a younger Donald Trump making lewd remarks about women and acknowledging he felt he had carte blanche to grab them by their genitals.

NBC News’ handling of Farrow’s investigation of Weinstein’s behavior — which was published by The New Yorker and was awarded a Pulitzer — has been under scrutiny for months. New attention to the matter was sparked last week by a statement from Rich McHugh, a former NBC News investigative reporter with whom Farrow worked to break the Weinstein story. McHugh in a statement alleged NBC News killed their efforts. “Is there anyone in the journalistic community who actually believes NBC didn’t breach its journalistic duty to continue reporting this story? Something else must have been going on,” McHugh said.

In October of last year, after the story had surfaced, Farrow appeared on MSNBC’s “The Rachel Maddow Show” and told its host, “I walked into the door at the New Yorker with an explosively reportable piece that should have been public.” He added: “Immediately the New Yorker recognized that, and it was not accurate to say that it was not reportable. In fact, there were multiple determinations at NBC that it was reportable.”

According to Lack, NBC News “convened an independent group of the most experienced investigative journalists in our organization to review his material with fresh eyes” after Farrow objected to NBC’s decision not to move forward with the story in its form at the time, “We asked them – tell us what, if anything, we can broadcast. But their conclusion was unequivocal – this story is not ready for air.”

Farrow responded to the memo with a tweet Monday night, calling it “false and misleading” for omitting women who were identified in the NBC version of his story. “The story was twice cleared and deemed ‘reportable’ by legal and standards only to be blocked by executives who refused to allow us to seek comment from Harvey Weinstein,” he wrote, adding that he “loved” his time at the network and praised its journalists, “many of whom have reached out to me in frustration.”

McHugh also took to Twitter to dispute NBC’s argument that the report was “objective and thorough,” given that he was never interviewed. “What journalistic ‘ethic’ would cause a news outlet to cancel that interview, not air the audio tape, and let one of the most defining stories of the decade walk out the door?” he wrote. “With many women coming forward with harrowing tales of assault and rape, whether in shadow or on record, we have a journalistic, human and moral obligation to continue reporting.”

NBC recently published a memo and "fact sheet" from Andy Lack regarding their handling of the Harvey Weinstein sexual assault story that was never aired. Here is my response: pic.twitter.com/H9RbsW78jB — Rich McHugh (@RichMcHughNBC) September 4, 2018

Others with some familiarity with Farrow’s reporting process also took to social media Monday night to push back on NBC News’ new disclosures. “The lengths NBC is going to lie about basic facts and avoid explaining their decision to drag their feet, threaten Ronan, wave Harvey’s oppo research in his face, spike this story, and force him to take it elsewhere is pretty revealing!” said Jon Lovett on Twitter. Lovett is a former White House speechwriter and founder of Crooked Media, a media company that produces podcasts centered on political commentary, who has in the past been identified as Farrow’s partner.

At the root of the schism between Farrow and NBC News was a disagreement over what elements the story needed to be put on the air. NBC News seemed determined that the story include an on-the-record, on-air account from someone with direct knowledge of harassment by Weinstein. NBC News said Farrow had not been able to produce such a witness. “The only victim willing to be interviewed on camera and name Weinstein was a woman who spoke anonymously in shadow and alleged he subjected her to verbal sexual harassment. Therefore, following widely accepted journalistic standards, Farrow’s NBC News editors, including the head of the investigative unit, did not believe his work was ready for broadcast,” NBC News said in its analysis of the matter.

The news outlet also took pains to show how much Farrow’s reporting had evolved after he and NBC News parted ways. “Farrow’s award-winning New Yorker article about Weinstein – published nearly two months after he left NBC News and five days after The New York Times piece – bore little resemblance to the draft script he produced at NBC News,” the analysis said. “In fact, The New Yorker piece cited the following victims by name: Asia Argento, Mira Sorvino, Rosanna Arquette, Lucia Evans, Emma de Caunes, Jessica Barth, and Sophie Dix. Not one of these seven women was included in the reporting Farrow presented while at NBC News. An eighth woman named in The New Yorker piece did engage with Farrow while he was at NBC News – but never gave NBC News permission to use her name.”

NBC News also made an attempt to show that its executives rebuffed multiple approaches by Weinstein and his attorneys. The movie executive and his proxies approached Lack, NBC News President Noah Oppenheim and MSNBC President Phil Griffin in various locales, including a Time Magazine party and the lobby of NBCUniversal’s headquarters at 30 Rockefeller Center. In all of these cases, including email outreach, the executives declined to hold conversations with Weinstein or told him and his attorneys that they would have ample opportunity to respond if the news organization was going to move forward with putting a story on air.

The memo serves to illustrate the souring of a relationship that began with high hopes — and the missed opportunities likely to result. NBCUniversal brought Farrow aboard in 2014 to work on an early-afternoon hour at MSNBC, hoping to corral a young diplomat and attorney whose sharp, progressive voice had started to gain a following on social media. MSNBC in early 2015 moved to orient its daytime schedule away from left-leaning issues and more toward centrist news coverage, and Farrow moved to doing investigative reports for NBC’s “Today.” Now, Farrow has broken several other big stories in The New Yorker — including one alleging harassing behavior by CBS Corp. CEO Leslie Moonves — and has struck a content deal to produce documentary programming for HBO.

“We regret the deterioration of NBC’s relationship with Ronan, and genuinely wish we had found a path to move forward together,” Lack told NBC News staffers.