In a combative exchange at a hearing Friday in Washington, D.C., a federal judge unabashedly accused career State Department officials of lying and signing clearly false" affidavits to derail a series of lawsuits seeking information about former Secretary of State Hillary Clinton's private email server and her handling of the 2012 terrorist attack on the U.S. Consulate in Benghazi, Libya. U.S. District Court Judge Royce Lamberth also said he was "shocked" and "dumbfounded" when he learned that FBI had granted immunity to former Clinton chief of staff Cheryl Mills during its investigation into the use of Clinton's server, according to a court transcript. The Department of Justice's Inspector General (IG), Michael Horowitz, noted ... in June that it was "inconsistent with typical investigative strategy" for the FBI to allow Mills to sit in during the agency's interview of Clinton during the email probe, given that classified information traveled through Mills' personal email account. "[T]here are serious potential ramifications when one witness attends another witness' interview," the IG wrote. The transparency group Judicial Watch initially sued the State Department in 2014, seeking information about the response to the Benghazi attack after the government didn't respond to a Freedom of Information Act (FOIA) request. Parallel lawsuits ... are probing issues like Clinton's server, whose existence was revealed during the course of the litigation.