Deputy Attorney General Rod J. Rosenstein is a short-timer at the Justice Department. And in one of his final acts — along with seeing the Mueller report through to its conclusion — he’s vouching for a superior on controversial decisions in the Russia investigation.

What could go wrong?

Rosenstein on Thursday granted a rare interview to the Wall Street Journal, the purpose of which was clearly to express confidence in embattled Attorney General William P. Barr, who has been criticized for his letter summarizing key parts of the Mueller report and more recently for saying at a Senate hearing Wednesday that the FBI spied on the Trump campaign in 2016. Special counsel Robert S. Mueller III’s team has suggested Barr’s letter was misleading and left out key information, while “spying” is a talking point that is favored by President Trump but decidedly not by Barr’s law enforcement colleagues. The narrative is building that Barr might be in the tank for Trump.

Rosenstein professed to be dumbfounded by that narrative.

“He’s being as forthcoming as he can, and so this notion that he’s trying to mislead people I think is just completely bizarre,” Rosenstein said.

He added: “It would be one thing if you put out a letter and said, ‘I’m not going to give you the report.' What he said is, ‘Look, it’s going to take a while to process the report. In the meantime, people really want to know what’s in it. I’m going to give you the top-line conclusions.’ That’s all he was trying to do.”

Rosenstein’s comments are notable because he’s one of the few figures involved in the Russia investigation with some bipartisan credibility. He is a Trump appointee as the Justice Department’s No. 2, but he also has drawn Trump’s ire as the overseer of the Mueller probe, which Trump has long argued is a “hoax” and a “witch hunt.” Rosenstein, in his few public comments, has taken on critics of the investigation and generally given Mueller broad berth.

To some degree, Rosenstein was already invested in Barr’s stewardship of the closing stages of the Mueller probe. He praised Barr’s nomination, despite Barr’s known history of criticizing the Mueller probe, and in that letter he joined with Barr in their controversial decision to exonerate Trump of obstruction of justice — even as Mueller declined to either charge or exonerate him.

But those things might have been expected of Rosenstein, given his role in the Justice Department and the Mueller probe. Granting the interview, on the other hand, is an especially strong statement that he didn’t necessarily have to make at such a crucial juncture.

And Rosenstein hasn’t always had the best luck with such decisions. At the other bookend of the special counsel’s investigation was Rosenstein’s decision to author a letter criticizing then-FBI Director James B. Comey that Trump used to justify his firing. Shortly after this, Trump admitted he was going to fire Comey regardless of Rosenstein’s thoughts and that he did so with the Russia probe on his mind. Reporting indicates Rosenstein felt used by Trump and that the episode had damaged his reputation. Via the New York Times:

In public, Mr. Rosenstein has shown no hint that he had second thoughts about his role — writing a memo about Mr. Comey’s performance that the White House used to justify firing him. “I wrote it. I believe it. I stand by it,” Mr. Rosenstein said to Congress last year.

But in meetings with law enforcement officials in the chaotic days immediately after Mr. Comey’s dismissal, and in subsequent conversations with colleagues and friends, Mr. Rosenstein appeared conflicted, according to the four people.

He alternately defended his involvement, expressed remorse at the tumult it unleashed, said the White House had manipulated him, fumed how the news media had portrayed the events and said the full story would vindicate him, said the people, who in recent weeks described the previously undisclosed episodes.

In his Wall Street Journal interview, Rosenstein reiterated that he believed in the content of the memo and had few overall regrets about his time as a public official, as it nears an end. “If you put something in writing, put your name on it and be prepared to stand behind it,” he said. “That’s been a theme of my career.”

Standing by your words, though, is only part of the equation. Vouching for the good faith of an individual who is embarking on a very fraught set of circumstances — and whose actions are under fire — is quite another. Rosenstein has now thrown in his lot with Barr, and he’ll find out whether that loyalty will be rewarded or won’t ... again.