ET's Kevin Frazier spoke with Nicholl on Tuesday, before 55-year-old Morgan ended up quitting Good Morning Britain after the incident. Nicholl -- who noted that she is a friend of Morgan's -- said she was surprised at his reaction to criticism from Beresford given his own outspoken comments over the years.
"I think the feeling to Piers is quite simple over here in Britain, he's a bit like Marmite -- you either love him or you hate him -- but Piers, he dishes it out, he's got to be able to take it too," she says. "So I think a lot of us were left quite surprised when he took his mic off. I think there was quite a lot of surprise when he took his mic off and stormed out the studio today after getting a bit of a talking to or a dressing down from his weatherman."
"I will tell you what, tensions have been running very, very high here, and when you tuned in and watched the TV on Monday, it was a very explosive interview," Nicholl says. "Piers was shouting, the guests were shouting, tensions were running high. I would imagine that Piers had probably not slept through the night, and watched the interview."
"I think many journalists at the moment are probably running on empty and I think at some point, we all have a breaking point and at that point, Piers snapped and I think also his Twitter feed, he is now saying he is the subject of racism," she continues. "And actually, there are a lot of racist comments about him on Twitter and I think he clearly feels in the firing line -- yes, he puts himself there -- but I think that perhaps that storming off the set was a moment where he needed to take a breather."
Nicholl talked about Morgan's point of view when criticizing the Duke and Duchess of Sussex.
"What I think I will say is this. Piers has come under [fire] ... over what many perceive to be the relentless bashing of Harry and Meghan and you will see if you follow him on Twitter -- even people like the cricketer, Kevin Pietersen, who is friends, will often tweet, 'Just leave them alone,'" she says. "Well, Piers' argument is, 'No, they don't want to be left alone. They are putting themselves in the public eye and, you know, I am going to go for them,' and he has done that repeatedly."
"Piers is a former newspaper editor, he is a brilliant presenter, he has enjoyed record ratings on breakfast TV and the audiences are higher than they ever have been," she also says. "To many, he is entertaining, to some, he is a heartthrob, and to many, he is pure theater, people want to tune in."
In a statement on Tuesday, TV network ITV said that Morgan made the decision to quit Good Morning Britain.
"Following discussions with ITV, Piers Morgan has decided now is the time to leave Good Morning Britain," the statement reads. "ITV has accepted this decision and has nothing further to add."
Morgan got plenty of criticism for his comments on Markle after her interview with Winfrey, in which she said she had suicidal thoughts at one point. The controversial journalist said on Monday, "I'm sorry, I don't believe a word she says. I wouldn’t believe her if she read me a weather report."
Beresford called Morgan out on Tuesday's Good Morning Britain.
"I think that we need to all take a step back," Beresford said, before referring to Morgan previously revealing that he knew Markle prior to her life as a royal. "And I understand that you don't like Meghan Markle. You've made it so clear a number of times on this program. And I understand that you've got a personal relationship with Meghan Markle, or had one and she cut you off. She's entitled to cut you off if she wants to. Has she said anything about you since she cut you off? I don't think she has, but you continue to trash her."
At this point, Morgan got up from his seat and walked off the set, declaring, "OK, I'm done with this. Sorry. See you later. Sorry, can't do this."
Beresford continued after Morgan exited the room, "This is absolutely diabolical behavior. I'm sorry, but Piers spouts off on a regular basis and we all have to sit there and listen -- 6:30 to 7 o'clock yesterday was incredibly hard to watch."
Piers Morgan just walked off the Good Morning Britain set (!!!) after co-presenter Alex Beresford defended Harry and Meghan and condemned Piers' treatment of them in yesterday's programming pic.twitter.com/mH75J8ND4O
Morgan later took to Twitter to respond to people calling out his hypocritical behavior after years of grilling guests and co-presenters on Good Morning Britain.
"I just prefer not to sit there listening to colleagues call me diabolical," Morgan replied to one commenter. He added that he "went for a little cool-down," and noted that he later came back to have a discussion.