Liberal journalist Matthew Yglesias thrashed the mainstream media's widespread dismissal of the Wuhan lab leak coronavirus theory, writing Wednesday it was a "genuinely catastrophic media f---up" that unfairly maligned Sen. Tom Cotton, R-Ark.

It marks yet another example of the media's turn on the origins of the deadly virus that has upended the planet and killed millions over the past 18 months.

The media error in this case, Yglesias argued on his website SlowBoring, largely arose from Cotton's early theorizing last year that the virus escaped the Wuhan Institute of Virology being conflated with the idea Cotton had accused China of purposefully releasing a bio-weapon.  That, along with Cotton's reputation as a China hawk, led news outlets to mischaracterize his arguments.

TED CRUZ MOCKS WASHINGTON POST AS ‘CLOWNS’ AFTER FACT-CHECK DECLARES WUHAN LAB LEAK THEORY ‘SUDDENLY’ CREDIBLE

Cotton from the outset of the pandemic questioned the official Chinese government accounting of the virus' animal origins, at the same time other theories arose that the Chinese may have purposefully engineered it

In an appearance on CBS' Face The Nation last February, Chinese Ambassador to the United States Cui Tiankai was asked about Cotton's charge "the virus may have come from China’s biological warfare program," which he dismissed as "crazy." Politico managing editor Blake Hounshell linked to his outlet's writeup of the exchange and said it was "wild to see [Cotton] spreading rumors about a Chinese bioweapon that were easily debunked within minutes."

"At this point, Cotton had achieved what’s really the greatest achievement possible for a Republican Party politician — he was unfairly maligned by the MSM," Yglesias wrote.

The Washington Post, New York Times, and others wrote last year that Cotton had embraced a "fringe" or "conspiracy" theory. The Times story, Yglesias noted, was "overwhelmingly about people who are not Tom Cotton saying something different from what Tom Cotton said."

EX-NEW YORK TIMES HEALTH REPORTER: ‘LAB LEAK’ CORONAVIRUS THEORY LOOKING STRONGER

"[The Times story] is also a reminder that this was a different era of Covid politics, because one of the reasons [the author] gives for doubting that it’s a deliberately engineered bioweapon (which again, is not what Cotton said) is that the virus isn’t really that big of a deal because younger and healthier people don’t have much to fear from it," he wrote.

Cotton noted several possibilities for the virus' origins in February, stating the notion China purposefully released the virus was highly unlikely.

CHRIS CUOMO SAYS ‘POLITICAL RIGHT’ OBSESSED OVER COVID ORIGINS TO ‘FORWARD AGENDA’ THAT CHINA WAS ‘SNEAKY’

Citing the Washington Post's Josh Rogin, one of the few mainstream press voices to delve into the lab theory over the past year, Yglesias wrote the chief problem was a small group of reporters and fact-checkers had declared a "scientific consensus" about the animal origins of the virus when no such consensus existed.

"Essentially Cotton said something that was then transformed into a fake claim of a Chinese bio-attack, then the fake claim was debunked, and then the debunking was applied to the real claim with little attention paid to ongoing disagreement among researchers," Yglesias wrote.

Numerous stories were written last year, including by Yglesias' old website Vox, assuring readers that the lab leak notion was false. The Washington Post published a fact-check video last year purporting to debunk the lab theory and quoting Peter Daszak, president of EcoHealth Alliance, praising the autocratic Chinese government as "incredibly open." Fact-checker Glenn Kessler publicly mocked Sen. Ted Cruz, R-Texas, for criticizing the fact-check and said the lab leak theory was "virtually impossible"; on Tuesday, Kessler published a new timeline about how the theory had "suddenly" become credible.

CLICK HERE TO GET THE FOX NEWS APP 

"Beyond the genuinely catastrophic media f---up, the actual policy stakes in this controversy are less clear to me," Ygelsias wrote, adding the story showed the perils of social media as a vehicle for complex scientific discussion.

Former President Donald Trump, former Secretary of State Mike Pompeo, and former Centers for Disease Control and Prevention Director Robert Redfield are among the prominent figures who believe the coronavirus escaped a lab.