The systemic failures in the FBI’s FISA process are sure to animate allies of President Donald Trump who have claimed that the surveillance tool was weaponized against the president’s campaign in 2016. But the findings also bolster arguments by critics of that claim who have suggested that errors in the Page application were likelier attributable to systemic sloppiness than sinister intentions.

For each of the 29 applications, Horowitz's team reviewed whether the “Woods procedures” for justifying an application were properly followed.

“We do not have confidence that the FBI has executed its Woods Procedures in compliance with FBI policy, or that the process is working as it was intended to help achieve the ‘scrupulously accurate’ standard for FISA applications,” Horowitz wrote in a “management advisory” addressed to FBI Director Chris Wray.

One troubling finding in Horowitz’s ongoing audit: The files providing detailed support for four of the 29 applications reviewed were missing.

“We could not review original Woods Files for 4 of the 29 selected FISA applications because the FBI has not been able to locate them and, in 3 of these instances, did not know if they ever existed,” he wrote.

Regarding the Page surveillance application, one key flaw the inspector general found earlier in renewals of the application was that the court was not advised of indications of problems with information from a key source.

The new advisory from Horowitz signaled issues about recordkeeping regarding such sources.

“Although there are specific requirements related to FISA applications that utilize [confidential human source] reporting, we have observed that these requirements are not being consistently followed,” Horowitz wrote.

The new evidence of flaws in the FBI’s surveillance practices are also likely to impact a lingering conflict between the House and Senate over reauthorizing unrelated FISA provisions that expired earlier this month.

Lawmakers left town before resolving discrepancies, which had proved nearly intractable amid factional tension in both chambers. Progressives, who view the FBI’s great surveillance power warily, found unlikely partners among Trump allies who sought sharp curbs on FISA surveillance in response to Trump’s claims of an FBI conspiracy against him.

The House ultimately passed a bipartisan bill that made some reforms to the FISA law, but it stalled in the Senate, which passed a short-term reauthorization of the provisions without reforms.

A response the FBI issued to a draft version of the new report said reforms Wray has already initiated should address many of the shortcomings found in the IG audit.

“We believe that the process errors identified in the OIG’s preliminary findings will be addressed by Director Wray’s previously ordered corrective actions,” Associate Deputy Director Paul Abbate wrote.

Abbate also said the FBI was assessing its “accuracy subfiles” for all FISA applications since 2015 and taking “remedial steps,” where appropriate.

The FBI’s response did note some limits on the IG’s review thus far. For example, the auditors have not canvassed the entire investigative case files related to each surveillance application, but simply searched for the separate files the bureau is supposed to maintain to prove the accuracy of its submissions.

Horowitz also offered some key caveats about his work. He said he's drawn no conclusion yet about the "materiality" of the errors in the applications his office reviewed. He also hasn't attempted to assess whether the sum total of evidence in each application met the legal standard for granting a surveillance order.

Horowitz also noted that his audit has been expanded recently to encompass how officials at DOJ’s National Security Division performed in their own efforts to ensure the accuracy of the FBI’s submissions.