WATCH: CNN panel bursts into laughter as Katrina Pierson steers sex assault denials into a ditch

Both Corey Lewandowski and Katrina Pierson crashed and burned as they tried to deny or explain away the latest sexual assault allegations against Donald Trump.

Jessica Leeds, a 74-year-old former businesswoman, claimed Trump aggressively groped her after he was seated next to her on a flight more than 30 years ago -- but his former campaign manager and his national spokeswoman furiously denied the allegations during a panel discussion on "CNN Tonight," hosted by Don Lemon.

"You have a woman who was in first class, where it's a fairly open area, making an accusation of someone who's saying, 'It's okay if he would have just touched the top half of my body,'" Lewandowski said. "Clearly, she wasn't offended by that, or at least intimated that would have been okay with her for some rationale reason, if this even took place. I think the whole thing, timing, is quite speculative, at best. I think it's very difficult, if you've been on an airplane -- I know you've been on an airplane -- sitting in first class, that someone would notice if an 'octopus' was grabbing you, and all of a sudden she's so enraged by this, she gets up and goes to the back of the plane. I think there's a lot of holes in this story."

CNN contributor Hilary Rosen, a Clinton surrogate, said there were just too many allegations piling up for the claims to be without merit -- and Trump's own words triggered the avalanche of accusations.

"Donald Trump sort of brought this on himself the other night by saying, 'No, I've never done this, unwanted advances, treated women with such disregard, assaulted them without their consent' -- and because he said that, all of these women that he did this to are now saying, 'Wait, wait, wait -- you did it to me, wait, wait wait, you did it to me,'" Rosen said. "So, Corey, you can try to pick each one of these apart, but you're just never going to be able to convince people that this huge group of women who all just got pissed off when he said that to everybody else."

Peter Beinart, a contributing editor for The Atlantic, said 12 women had now come forward to accuse Trump of actions quite similar to those he boasted about to former "Access Hollywood" host Bill Bush.

"My question for you, Corey and Katrina, do you really want to spend your evenings for the next few weeks trying to pretend all of these 12 women are lying?" Beinart said. "Don't you have something better to do?"

Katrina Pierson launched an attack on the New York Times, which reported the Leeds allegations, but Lemon insisted that she say whether she believed the woman's claims.

"This is what happens to Trump people," Pierson complained, as Lemon repeated his question. "I do not believe it at all. It is 100 percent, patently false, and as I was saying, this is the exact same New York Times that tried the same stunt back in March, and then those women came forward and debunked that article."

Pierson then launched into a discussion of what types of planes and armrests were in use in the early 1980s, when the alleged incident took place, and both Beinart and Rosen burst into laughter as the Trump surrogate tried steering the discussion deep into the weeds.

"If she was groped on a plane, it wasn't by Donald Trump, and it certainly wasn't in first class," Pierson said.

Beinart, still laughing, said Pierson's sleuthing might have debunked Leeds' claims, but he said that was just "one down, 11 to go."

"Donald Trump had his own plane in the '80s, he doesn't fly commercial," Pierson said.

Rosen asked what the women had to gain by coming forward, and Pierson said they were seeking fame.

"Fame?" Rosen said. "That woman looks like she's looking for fame? I don't think so."

Leeds told at least one person about her accusations shortly after the alleged incident, and she began speaking about it again more than a year ago as Trump launched his presidential campaign.

"She came out with it like so many other people in the past," Pierson said. "You attack Donald Trump and the media puts you on TV to tell your fake story just to get debunked a few days later. That's exactly what's happening here. This story did not happen. I just told you why. The fact that we're talking about this instead of what WikiLeaks has brought out about Hillary Clinton is just absurd."

Lemon reminded Pierson that the previous segment of his program was devoted to the WikiLeaks allegations, and Beinart pointed out that 11 other women had come forward with very similar allegations against Trump.

"You're going to say that they were also on planes?" Beinart said. "It's just ridiculous -- it's laughable at a certain point. We're in Bill Cosby territory now."

Pierson said if those women were truly concerned about the way Trump had treated them, why wait until 26 days out from the presidential election -- and Rosen reminded her that Trump had brought four women to the presidential debate who had previously accused Bill Clinton of sexual misconduct.

"That already raised the tension level of other women, like, what is he doing, why is he bringing this up -- the country doesn't want to talk about this -- and then during the debate, he denied that he ever acted that way," Rosen said. "All of these women have come out now to say, wait a minute -- of course, you acted this way. They would have been quiet if he had not said that he had never done anything. That's what every one of them has said."