Hillary and Chelsea Clinton made a rare joint late-night appearance on The Late Show Monday evening to promote their new Book of Gutsy Women, which takes a historical look at women who helped change the world for the better. But of course, host Stephen Colbert couldn’t help but get the former secretary of state’s reaction to the latest developments in the Trump whistleblower scandal.

Moments before the Clintons joined Colbert on stage at the Ed Sullivan Theater in New York, The Wall Street Journal reported that current Secretary of State Mike Pompeo was listening in on President Trump’s phone call with the Ukrainian leader that has now prompted a formal impeachment inquiry—despite the fact that he previously pleaded ignorance about the whistleblower complaint.

“How many times when you were secretary of state did you have to say to Obama, ‘You can’t extort foreign countries to get dirt on your political enemies?’” Colbert asked, prompting a belly laugh from Clinton.

“Yeah, that never happened,” she replied, shaking her head. She added that the secretary of state’s job in that moment is to “make sure he knows, number one, what the president is going to say on those calls,” implying that the Trump administration may not be as “prepared” for talks with foreign leaders as the previous White House was.

But “because you’ve got a president who doesn’t listen to anybody and doesn’t follow instructions whatsoever,” Clinton said, “I’m not sure they haven’t just given up on trying to give him any sort of preparation.”

From there, Clinton pushed back on the “Republican defenders” of the president who are claiming the charges against him are “hearsay.” As she put it, “It was an admission from the White House! I mean, the transcript of the phone call was put out by the White House. And the whistleblower has a depth of understanding that needs to be taken seriously about what happened.”

“I think if the secretary of state was on the call as is now being reported, he should have been one of the very first people to say, ‘Wait a minute, we’ve got to clean this up. You can’t let that stand,’” she added. “But we don’t know what he did.”

As for Rudy Giuliani, who has been reportedly running what amounts to a shadow State Department on behalf of Trump, Clinton said, “That would be a big problem” if it had happened under Obama.

“Presidents often use—as do secretaries of state—they might use an envoy or a special adviser to deliver a message,” she said. “But again, it is supposed to be carefully thought through. And from what we’ve seen on television, carefully thinking through is not one of Rudy’s strong points.”