Buzzfeed probably has some details wrong, but is mostly correct. Notice that Mueller's spokesman did not say the whole thing is wrong. Just like the most sensational (and unimportant) parts of the dossier have not been proved: Their is still independently documented evidence in it that shows a pattern of criminality. If the subject was anybody but the President, he would have been prosecuted under RICO long ago.

And even if Trump did not tell Cohen to lie, Cohen surely made up a false narrative and told it to everyone. Trump most likely used that false narrative in his written answers to Mueller. Then Cohen came clean to the Grand Jury, to get his sentence deal. And we are left with Trump committing perjury in writing, shown by Cohen's testimony and multiple emails and documents in Mueller's possession. I'm sure that Trump is very much a practitioner of "let's get our stories straight before we go to court" from his past court appearances.

Cohen is a rat because he changed his story after getting everyone to use his false narrative.