The Cohen sentencing agreement does give the impression, at least, that Cohen lied "in accordance with Client 1's directives", and the statement from the Special Council's office yesterday does not deny the possibility that Trump told Cohen to lie.
The statement from the Special Council's office states that the Buzzfeed report was "not accurate". The two journalists have to have got something wrong. Both the chief editor of Buzzfeed, as well as Anthony Cormier, the non-controversial of the two journalists, were interviewed by phone on MSNBC last night. The editor stands by the story. Cormier stated that it was he, not Leopold, the journalist with the checkered past(although he was a finalist for a Pulitzer for his reporting) who confirmed what their two sources were saying. Without seeing the "documents", I'm not sure how that confirmation could be had, but, at any rate, that's their position at the moment.
We are not going to see Buzzfeed out their sources. And despite Buzzfeed's editor asking for clarification from the Special Council's office, we are not going to see further statements from Mueller's team.
It took 24 hours for Mueller's office to issue their rare rebuke of a published report. No doubt they spent some time ensuring those sources were not from within their own office. They have consistently been leak proof from the start.
I think the rebuke came, not just because the report was "not accurate". In April, 2018, following reports that Cohen had been in Prague, Mueller's office issued a statement telling the press to check their sources carefully because not every story being published was accurate. So Mueller's office has urged caution before.
I think yesterday's rebuttal was not just because Buzzfeed's report was not 100% accurate, though Buzzfeed says otherwise, but also due to the "impeachment hysteria" that overcame both journalists, and, I think more importantly, Democratic members of Congress. If the report was not completely accurate, Mueller would want to be sure nobody thought this leak originated in his office, and Mueller would not want "impeachment hysteria" overwhelming the House. If any conclusions of the report were accurate, such as Trump telling Cohen to lie, Mueller wants that info released on his terms, and his timetable.
I think the "impeachment hysteria" struck Mueller as too serious not to tamp down. Since it was based on a report containing inaccuracies, his office felt obligated to shoot it down. In time, we will see if any of it was accurate. In the meantime, it's a black eye for journalism, and Trump's team will use it going forward.