Katie Couric said Tuesday that she has "no relationship" with Matt Lauer, her longtime "TODAY" co-host who was fired in 2017 amid sexual harassment accusations.
"You know, that was really, really hard. It took me a long time to process what was going on. The side of Matt I knew was the side of Matt you all knew," she said.
"As I got more info and learned what was going on behind the scenes, it was really upsetting," she added. "I realized there was a side of Matt I never really knew."
In a wide-ranging interview with Savannah Guthrie ahead of the release of her book, "Going There," Couric talked about Lauer, the news that she chose not to use part of a 2016 interview with Ruth Bader Ginsburg and how she did not extend herself to some women in the news industry because of fears that they might take her job.
In the book, Couric wrote that she texted Lauer after he had been fired.
"I am crushed. I love you and care about you deeply. I am here. Please let me know if you want to talk. There will be better days ahead," she wrote, according to a copy of the book shared with NBC News before it goes on sale Oct. 26.
Lauer replied with a blowing-kisses emoji, according to Couric.
She wrote that "it felt so heartless to abandon him, someone who'd been by my side, literally, for so many years." But she acknowledged that she had also heard "the whispers" about her co-anchor's behavior.
"The general rule at that time was: It's none of your business," Couric wrote, and she expanded on the thought in the interview.
"There's always gossip in TV news," she told Guthrie. "I think it was a very permissive environment in the '90s, and I think permissive environments often result in serious transgressions, and I think back then, it was sort of like you felt like it was none of your business, and nobody ever came to me to talk about it."
Couric added that "our notion of what a consensual relationship is has changed dramatically, and you have to consider the power dynamics."
But now, she admits, she had trouble understanding why Lauer "behaved the way he did, and why he was so reckless and callous and honestly abusive to other women."
NBC News fired Lauer in November 2017 after Brooke Nevils, a former NBC News producer, made a detailed complaint accusing him of inappropriate sexual behavior during the 2014 Winter Olympics in Sochi, Russia. In a statement at the time, Lauer said he was "truly sorry."
In a book published after Lauer's firing, Nevils told investigative journalist Ronan Farrow that Lauer raped her while they were in Sochi. Lauer denied the accusation, claiming that his sexual encounters with Nevils were "completely consensual." (Farrow is a former NBC News employee who now writes for The New Yorker.)
Couric has also drawn scrutiny for another part of her book. She wrote that she decided not to use a part of her 2016 interview with Ginsburg after the late Supreme Court justice spoke in negative terms about Colin Kaepernick and other athletes who knelt during the national anthem to protest racial injustice.
The final version of the interview, published by Yahoo News, includes Ginsburg saying she believed kneeling during the anthem was "dumb and disrespectful." But it leaves out Ginsburg's harsher criticism of Kaepernick and other athletes, Couric wrote.
Couric, who was a global anchor at Yahoo at the time of the interview, wrote that she cut some of Ginsburg's comments to "protect" the liberal icon.
In recent days, some media critics have faulted Couric for editing the interview. Erik Wemple, a media critic for The Washington Post, wrote a column with the headline "Katie Couric 'wanted to protect' Ruth Bader Ginsburg. That wasn't her job."
Couric addressed the criticism Tuesday.
"I think what people don't realize is we make editorial decisions like that all the time," she said. "And I chose to talk about this and put it in the book for a discussion."
She said that she didn't completely understand what Ginsburg had meant by the excluded comment but that she should have asked for clarification.
"I ultimately I think I should have included it, but I think it's really important to look at what I did include," Couric said.
Couric, who also anchored "CBS Evening News," said that "early on, I encountered a lot of sexism."
"It was a very male-dominated industry run by men," and there were "very few positions for women."
She said the climate caused her to be "territorial" and "insecure," preventing her from mentoring or providing guidance to other women, in fear that they might become threats.
"I think I just wish I had extended myself more and showed people the ropes a little bit more," Couric said Tuesday. "But I think when people are outwardly kind of vying for your job, it is hard to be generous."