Basically, every FISA application makes assertions of fact, which are presented to the FISA court, the FISC, in support of the application. Naturally, those assertions of fact are supposed to be supported by, well, evidence that can be confirmed. Horowitz says:
As a result of our audit work to date and as described below, we do not have confidence that the FBI has executed its Woods Procedures in compliance with FBI policy. Specifically, the Woods Procedures mandate compiling supporting documentation for each fact in the FISA application. Adherence to the Woods Procedures should result in such documentation as a means toward achievement of the FBI’s policy that FISA applications be “scrupulously accurate.”
OK, fair enough. The FBI hasn't been "scrupulously accurate." Mistakes were made. But that doesn't mean that jobs will be lost, or anything drastic like that. Scrupulosity is for small minded people, anyway. The FBI maintains that the mistakes weren't "material", and maybe that's the point. Under the FISA regime, mistakes are mostly administrative miscues. That's the beauty of FISA: no real accountability for the bureaucrats. Isn't that the ultimate bureaucratic dream?