ANOTHER SECURITY BREAKDOWN AT THE FBI: “The FBI’s famed National Academy recently expelled a student from a troubled African nation after learning he was not a cop, as he had claimed, The Post has learned. The incident raises serious questions about the FBI’s screening process for prospective National Academy students. . . . The ‘quiet’ Sinie lived, studied at and strolled around the Quantico facility with a still and video camera for 91/2 weeks before he was found not to be a cop, expelled and sent home to Chad, sources said.” Well, that’s comforting.