Corey Lewandowski's mission in a CNN interview on Monday was clear: Don't give away anything that might advance the narrative of a divided campaign that has descended into chaos since Donald Trump secured enough delegates to be the presumptive Republican presidential nominee.

So when Dana Bash asked why Trump fired Lewandowski earlier in the day, the ex-campaign manager said he didn't know and pivoted instantly to a familiar talking point about the candidate's "historic" achievements in the GOP primary. And when she asked about his relationship with campaign chairman Paul Manafort, against whom he reportedly lost a power struggle, Lewandowski insisted "there was no animosity."

But when Bash asked about a "Wizard of Oz"-inspired tweet sent by campaign adviser Michael Caputo, she managed to get a very telling response.

[Update: CNN is reporting that Caputo has resigned from Trump's campaign because of the tweet above.]

This was the exchange:

BASH: I don't mean to put that up to be hurtful to you, but it's just the reality.
LEWANDOWSKI: Well, let's just be clear: Michael Caputo is not a senior adviser. He has no formal role with the campaign. He's a volunteer, and so he doesn't get paid by the campaign; he has no formal role with the campaign. So he's entitled to his own ...
BASH: But for anybody involved in the campaign and wants the best for Donald Trump, as you do, to put that out ...
LEWANDOWSKI: He's not involved. He's not involved is the problem.
BASH: But I wouldn't have put that up had that not been a narrative that we were hearing, and I'm sure that's why you wanted to come on — to try to push back on a lot of that.
LEWANDOWSKI: I think in all campaigns, you've got detractors and you've got supporters. That's the nature of the beast. I think if you went out and talked — look, I don't know Michael Caputo. He's a volunteer who's been with the campaign for three or four weeks. I think he's actually in Cleveland. I don't really know what he does for the campaign. But if you talk to the people who've been here from the beginning, you looked at the state directors who've been here from the beginning, the people who have been in the trenches, who understand and have seen Mr. Trump's work ethic and what he's been able to accomplish in their states — whether it's New Hampshire or Nevada, South Carolina, Iowa or any of those early states, where no one gave him a chance, and he went out and became successful and became the Republican nominee — I think if you asked them, they'd stand toe to toe with me any day of the week and 20 hours a day to make sure they have the same work ethic I do. And I think that's what I try to foster with the people I work with.

Lewandowski had kept his cool until this point, even when Bash asked him about the perception that he is a "hot head." But Bash appeared to throw him off-script by triggering an emotional response to Caputo's mocking tweet. Lewandowski's job here — perhaps his final job on behalf of Trump — was not to disparage anyone still working on the campaign.

Yet he couldn't resist a shot at Caputo — a veteran Republican consultant who, by the way, has reportedly had Trump's ear for a few years, meeting with the real estate magnate in 2013 to discuss the possibility of a bid for New York governor. Caputo is indeed unpaid, according to filings with the Federal Election Commission, but he has been part of Trump's presidential campaign operation for months, not weeks. Last month, Politico obtained and reported on a memo Caputo sent to Trump spokeswoman Hope Hicks and a researcher at the Republican National Committee in which he requested dirt on Hillary Clinton "for immediate use and for the afternoon talking points process."

Lewandowski's assertion that Caputo is "not involved" in the campaign just doesn't hold up.

And when he took a break from belittling Caputo's role to defend his own conduct, Lewandowski said something revealing. He suggested Bash should "talk to the people who've been here from the beginning." He didn't say she ought to talk to anyone within the campaign. He referred only to the original team — as in people other than Manafort, Caputo and the other relative newcomers whose influence appears to be growing.

Without meaning to, Lewandowski reinforced the idea that there is a split within the Trump campaign between the rag-tag band that got the candidate off the ground and the professional operatives who joined later. A good question from Bash — one that touched Lewandowski on a personal level — got him to reveal more than he planned.