CNN anchor Jake Tapper joined Stephen Colbert on “The Late Show” Tuesday night and explained why he responded to Bill O’Reilly’s tweeted jab about ratings.

“Fact check: Our ratings are fine,” Tapper told Colbert. “He just wanted to take a shot at me because I had been mentioning him as a sexual predator on air when we were covering the Harvey Weinstein scandal and also pointing out that Weinstein is not the only one. O’Reilly and [Roger] Ailes were horrific sexual predators at Fox.”

“I’m a journalist so I like to explain things,” added Tapper. “I felt he was using the word ‘low’ incorrectly.”

O’Reilly had tweeted that Tapper had earned “low” ratings on CNN, which prompted Tapper to tweet back, writing, “‘Low’ would be sexually harassing staffers and then getting fired for it — humiliated in front of the world. Now THAT would be low.” Tapper was referring to the sexual harassment allegations against O’Reilly, which resulted in O’Reilly’s firing from the news outlet.

O’Reilly was recently dropped from his talent agency UTA after it was revealed that he had settled a lawsuit for $32 million in January of this year. Despite knowing of the settlement, Fox News re-upped his contract by $5 million just one month later. O’Reilly received a $25 million payout upon his termination in April.

Watch the full clip below.