They skate as a matter of law
But the illegality is the perjury used to obtain the warrant, right? And isnt there more impact in the potential charge of abuse of power that Greg Jarrett keeps citing?
The only oath in the application is by the investigator. The DOJ role is approval, which amounts to making sure the contents satisfy the form.
I suspect the oath in this case is that the material in the warrant is true to the best of knowledge. Lie by omission is not a violation of the oath.
-- ... isn't there more impact in the potential charge of "abuse of power" ... --
Abuse of power isn't the name of a crime, although some crimes, like deprivation of civil rights, follow from what is properly viewed as abuse of power.
The FISA context changes the way the law is usually applied. It's nominally a crime to use FISA to deprive a person of fourth amendment or first amendment right. But then the law provides a defense to the key players ...
50 USC 1809 - Criminal Sanctions
(a) A person is guilty of an offense if he intentionally--
(1) engages in electronic surveillance under color of law except as authorized by this chapter ...(b) Defense
It is a defense to a prosecution under subsection (a) that the defendant was a law enforcement or investigative officer engaged in the course of his official duties and the electronic surveillance was authorized by and conducted pursuant to a search warrant or court order of a court of competent jurisdiction.
FISA warrants are issued to get around the fourth amendment when the purpose of the surveillance is to get foreign intelligence. The legal framework is radically different from the typical warrant used to investigate potential crimes.
FISA invites abuse. It is a deliberately secret process, and we are supposed to have blind trust in it. The contention that Congress can conduct meaningful oversight to the process is risible. The process is operated by investigators and courts. Bad warrants have been challenged. The challenger always loses.