Former Washington Post Fact Checker Acknowledges Piece He Was 'Completely Wrong About'

Leah Barkoukis | August 18, 2025 9:00 AM

Former Washington Post fact-checker Glenn Kessler said he has “infinite regret” over a 2020 headline casting doubt on the theory that COVID-19 leaked from a Chinese lab.

During an interview last week with journalist Ira Stoll, Kessler, who recently launched his own Substack, was forthright about his error.

“Everyone makes mistakes. No one is perfect. And when you’ve got a title like ‘the fact checker,’ when you make a mistake, people notice. So, you know, you’ve got to own it,” Kessler said.

He explained co-author Sarah Cahlan warned him about the language he used in the piece.

"One of the reporters on the piece came up to me the next day and said, ‘I think you made a real mistake by putting 'it's doubtful' here. Because I'm uncertain where it stands, and you framed it in a way that made it seem more definitive than what we came up with,’" Kessler recalled of the headline that read: "Was the new coronavirus accidentally released from a Wuhan lab? It’s doubtful."

"That's on me," he continued. "I screwed up. She recently left the Washington Post to go to another place. In my goodbye remarks, I mentioned, this explains why you should always listen to Sarah, because she's right, and I was completely wrong about this."

The original fact-check claimed that scientific evidence at the time "strongly supports" the theory that COVID-19 came from nature and that "too many unexpected coincidences" would have been needed for a lab leak. However, it added that the Chinese government was unwilling and unable to offer more information on the theory.
Though Kessler now says the fact-check mostly focused on bioweapon claims, he wrote on Twitter, now known as X, in 2020 that it was "virtually impossible" for COVID-19 to have come from a lab in a comment to Sen. Ted Cruz, R-Texas, about the piece.
"I fear @tedcruz missed the scientific animation in the video that shows how it is virtually impossible for this virus jump from the lab. Or the many interviews with actual scientists. We deal in facts, and viewers can judge for themselves," Kessler wrote.
Kessler wrote a new fact-check in 2021 that the lab leak theory "suddenly became credible" after new evidence emerged. Though several members of the first Trump administration expressed support for the theory in 2020, Kessler blamed them for his rejection of their claims. (Fox News)