Several reporters who cover the Justice Department said they interpreted the statement as a full denial of BuzzFeed’s conclusions. Mr. Smith, in the interview, said the wording of Mr. Carr’s statement was imprecise, adding that he was “eager to understand” which specific aspects of the article the special counsel’s office had denied. Asked if the statement had caught him by surprise, Mr. Smith replied, “You always have to be ready for everything in this business.”

BuzzFeed News, the reporting division of a website better known for viral videos and quizzes, has scrambled for respect and recognition since its founding eight years ago. Under the direction of Mr. Smith, a longtime political journalist, the site has pursued ambitious stories. Last year it was a Pulitzer Prize finalist for an inquiry into the deaths of Russians in England, which Mr. Leopold worked on.

BuzzFeed’s longtime investigative editor, Mark Schoofs, left in October for an academic post at the University of Southern California. His replacement, Heidi Blake, who is based in London, edited the Cohen piece, along with Mr. Smith and Ariel Kaminer, a senior investigations editor, both of whom are based in New York.

This is not the site’s first brush with controversy. In January 2017, Mr. Smith was the first editor to publish the explosive, but unverified, dossier compiled by the former British intelligence officer Christopher Steele during the 2016 campaign. Besides earning ire from the White House, and some scolding from media ethicists, the site was also sued for libel by Mr. Cohen in a case that was later dropped. Last month, a federal judge ruled in favor of BuzzFeed in a separate dossier-related lawsuit.

Mr. Leopold, who is based in Los Angeles and known for his mastery of Freedom of Information laws, has a self-described “checkered past” in journalism that includes retracted reporting and accusations of plagiarism. In 2006, he reported for TruthOut.org, a liberal website, that Karl Rove, a senior adviser to then-president George W. Bush, would soon be indicted; the story proved false. Mr. Leopold has also spoken openly about his recovery from addiction. Asked about Mr. Leopold’s past, Mr. Smith pointed to his Pulitzer Prize nomination last year.

The contentiousness over the recent BuzzFeed article is unlikely to abate soon.

Its central assertion pleased many liberals impatient for Mr. Mueller to release his findings. Democratic lawmakers were quick to write on Twitter that, “if true,” the article’s findings could lead to impeachment. In covering the reaction to its own scoop, BuzzFeed ran the headline, “More And More Democrats Are Suggesting Trump Should Be Impeached After He Told His Lawyer Michael Cohen To Lie To Congress.”

The cold water of Mr. Carr’s denial led some journalists to cringe on-air in real time. “This is a bad day for us,” the CNN legal analyst Jeffrey Toobin said on Friday, after his network had devoted many segments to dissecting the piece. “It reinforces every bad stereotype about the news media.”