The reason that CIA agents needed liability insurance related to their work as interrogators is that they realized they were being lied to about the law. They knew that they could not rely on the patsies of this Administration to tell them the truth about what was legal and what was not.
So they needed some kind of protection, and the liability insurance was it.
The good news about all of this is it implies that people are refusing to use torture in interrogations anymore without legal protection. Now that they have legal immunity that may have changed, but not by much. Everyone knows an election is coming up and a sea change is near. How long will an immunity last? How will it be interpreted? Such questions are natural ones for people taking the risks of prison, which I can assure you do not include our Attorney General, Mr. Torture himself.