FTA:

"Moreover, the FBI did not believe that including the informant’s criminal history would have changed the judge’s decision to issue a warrant to search Cole’s home, prosecutors said. In fact, the DOJ argued that the FBI’s use of the informant for more than 16 years suggests that the FBI consistently found the informant reliable."

That isn't the FBI/DOJ's determination to make. I've seen paragraph's first sentence in other FBI related articles about similar cases before. Makes one wonder, how long and how effectively has this sort of play been "prosecuted" throughout FBI's history.