A former top judge on the U.S. Foreign Intelligence Surveillance Court says he expects a "very fair" report from Justice Department Inspector General Michael Horowitz on alleged Foreign Intelligence Surveillance Act abuses by the DOJ and the FBI.

U.S. District Judge John Bates, who was placed on the FISA court by Supreme Court Chief Justice John Roberts and was its presiding judge from 2009 to 2013, sat down with Lawfare editor-in-chief Benjamin Wittes last week to discuss all things FISA, including the recently completed investigation into the application process to obtain warrants to electronically surveil onetime Trump campaign aide Carter Page.

Though Bates said he did not have any insider knowledge on the contents of the report, which was given to the DOJ and FBI for a classification review two weeks ago, he laid out his expectations based on what he knows about Horowitz.

"I expect a very thorough report — a very fair report from Michael Horowitz. He's a good inspector general. He's careful," Bates said. Bates added later that he expects the report to be "pretty lengthy."

Bates' assessment of Horowitz bolsters the watchdog's credibility at a time when he will find himself yet again at the center of a political firestorm when the FISA report is released to the public in the coming weeks.

The inspector general has already been criticized by one person scrutinized in the report: former FBI Deputy Director Andrew McCabe, who was fired last year after a report from Horowitz found he made unauthorized disclosures to the media and misled investigators. In a legal fight against the Justice Department over his ouster, McCabe's lawyers slammed Horowitz's report as being "deeply flawed."

Horowitz has been talking with U.S. Attorney John Durham, who is handling any criminal referrals from the investigation. As to what exactly the report says, Bates could not guess.

Bates acknowledged there being a "rumor mill" coming from the Right — Republicans and conservative media who allege federal officials misled the FISA court in their use of an unverified dossier compiled by British ex-spy Christopher Steele about President Trump's alleged ties to Russia to obtain the Page warrants. But Bates also cited a recent hearing on FISA in which House Judiciary Chairman Jerry Nadler, a New York Democrat, dismissed allegations of FISA-related wrongdoing, saying, “I’m not aware of any terrible problem with the FISA court and specifically not with the Carter Page application."

"I don't have a prediction for whether he is going to find fault and mistakes or worse and at what levels. Because remember that the sign-offs on these applications in the Department of Justice and the FBI were pretty high levels," he said.

Bates listed off some of those officials — former FBI Director James Comey, McCabe, former Deputy Attorney General Rod Rosenstein, and former Deputy Attorney General Sally Yates — before noting, "Now how close scrutiny they gave to them, I don't know."

In the event that the FISA report is "factually based and concludes that the court was misled" and any other "failings," Bates said, "I think that the court is going to have to look at it and see what if anything it needs to do to improve the system for the future." He also questioned whether Senate Judiciary Committee Chairman Lindsey Graham's idea to press Chief Justice Roberts to crack down on possible abuse of the FISA court was "viable."