President Trump Thursday afternoon accused four former FBI officials of “treason” for their conduct in the early days of the Russia investigation. Thursday night, he handed his Attorney General William P. Barr sweeping powers to declassify information and intelligence to conduct a review of the situation.

What could go wrong?

The answer to that is plenty, if past is prologue. While the public has an interest in learning more about how this investigation got off the ground, we’ve already seen how situations such as this — including in the Russia probe — can lead to a cherry-picking of facts to create a misleading and politically expedient narrative. And Barr’s own conduct and past comments about this whole situation don’t exactly suggest a studiously neutral arbiter of what the public needs to know.

The most pertinent example of this is Barr’s stewardship of the Mueller report, for which his initial summary drew a remarkable written rebuke from special counsel Robert S. Mueller III himself. Even before we found out Mueller had weighed in, though, we could see from the report itself that Barr had offered a Trump-friendly and often misleading preview of the report.

He had said Mueller didn’t reach a conclusion on obstruction of justice, when in fact Mueller said he decided he couldn’t accuse Trump of a crime regardless of the evidence. He said Trump had been cleared of “collusion,” when in fact Mueller’s report explicitly said it wasn’t dealing with collusion and that the evidence of a conspiracy was insufficient rather than exonerating. Etc.

Barr has also made comments that suggest he’s quite sympathetic to the idea that there was some kind of conspiracy here. He has repeatedly called what the FBI did vis-a-vis former Trump campaign adviser Carter Page “spying,” even though the intelligence community bristles at that characterization, and FBI Director Christopher A. Wray said the term isn’t apt. Barr gave a recent interview to Fox News in which he repeatedly called what the FBI had done “strange” and said the explanations weren’t adding up. And he said, as early as 2017, that the FBI was “abdicating its responsibility” by not looking into “various ‘national security’ activities carried out during the election.”

That last comment, notably, came before many in the Republican Party adopted this conspiracy theory. And it even came before the release of the so-called Nunes memo, which had offered the most detailed case for a conspiracy to date.

That Nunes memo is also an example of how evidence can be cherry-picked or cleverly characterized to paint a slanted picture. The memo, which had to be declassified like the information Barr can now declassify, essentially argued that the FBI’s surveillance of former Trump campaign aide Page relied upon dubious, politically tainted evidence in the form of the Steele dossier.

It noted that the FBI’s FISA warrant application to monitor Page had not disclosed that the Steele dossier was funded by Democrats. In fact, as we later found out, it did disclose that the dossier’s origins were political — it just didn’t name names. Given that, it wasn’t difficult to surmise that Trump’s political opponents were behind it. So the Nunes memo was strictly accurate on that point, but it left out some very important context.

The Nunes memo also said former FBI deputy director Andrew McCabe had testified privately that the Steele dossier was essential to the FISA application, but it curiously didn’t quote him. Both Democrats on the committee and later McCabe disputed that characterization. And there were other issues, too.

Barr has tasked a respected U.S. attorney, John Durham, with reviewing these matters. It’s entirely possible a fair review will be conducted. But Barr has shown a notable willingness to believe in the nefariousness of how the Russia probe was launched. He has also telegraphed a desire to protect Trump’s prerogatives. And we’ve seen from both the Nunes memo and Barr’s own handling of the Mueller report just how selective disclosure of technically accurate facts can paint a distorted picture of some very complex matters — matters that are ripe for mischaracterization.

Except in this case, unlike the Mueller report and the Nunes memo, we may not ultimately get to see the fuller picture.