But now there has been a change from "if it is true" to "what is false". The office of special advisor Robert Mueller said that on Friday night the story contained information that "is not accurate."
The special advisor took the extremely rare step of issuing a statement and purposely cast doubt on BuzzFeed's story. But BuzzFeed says the special council should explain what exactly is inaccurate.
That is unlikely to happen. Meanwhile, BuzzFeed is exuding confidence about its original story, even when journalists in other newsrooms express doubts.
On Saturday, a spokesman for the news division said: "As we have reconfirmed our reports, we have not seen any indication that any specific aspect of our story is inaccurate, we trust what we have reported and we will share more as we can."
The story is still prominently displayed on the BuzzFeed News home page: "President Trump directed his lawyer Michael Cohen to lie to Congress about the Moscow Tower project."
The caption says "Trump received 10 personal updates from Michael Cohen and encouraged a planned meeting with Vladimir Putin."
BuzzFeed added a line on Friday night noting that the special lawyer's office had "disputed aspects of" the story.
No other major news media has been able to match the BuzzFeed reports, which were attributed to "two federal law enforcement officials."
But Smith, speaking in "AC360," pointed out that reporters Jason Leopold and Anthony Cormier had been "very much ahead" in stories about Trump Tower Moscow that were later confirmed.
Smith said he knows the identities of the two sources in Thursday's story. "We have a lot of confidence in these specific sources," he said.
However, BuzzFeed also has its defenders. Many observers see this as an unsolved mystery.
"The best thing is that, in the long term, the BuzzFeed piece will prove to be the right stadium, the wrong entry," veteran investigative reporter David Cay Johnston told CNN Business.
President Trump and his allies are using the controversy to attack not only BuzzFeed, but the national media in general.
Toronto Star's fact checker, Daniel Dale, noted that Trump told reporters Saturday morning that "the mainstream media have really lost their credibility," but then, two sentences later, they lied for the 13th time that the New York Times issued a post-election apology for its coverage. The Times never apologized. "
On social media, some Trump supporters celebrated the BuzzFeed controversy by calling it "BuzzFraud." Fox News went with "Buzzkill" in a headline. The Drudge Report was with "Buzzbleed!"
This, in turn, caused some strong defenses.
CNN's national and legal security badyst, Susan Hennessey, said Cohen will have an opportunity to solve the mystery sooner rather than later.
Cohen's hearing is scheduled for February 7.