The first contradiction pits former Secretary of State Hillary Clinton's explanation of security conditions at the compound against that of Eric Nordstrom, the former regional security officer at the U.S. Embassy in Tripoli.

CNN: Obama has explaining to do on Benghazi

Hicks -- praised by Republicans as a "whistleblower" -- was joined at the witness table by Eric Nordstrom, a former regional security officer in Libya, and Mark Thompson, the State Department's acting deputy assistant secretary for counterterrorism.

CNN: Doomed Libya ambassador: 'We're under attack'

Timberman said the State Department teams working out of the provincial capital, Hillah, were grounded most of the time because the State Department regional security officer would not permit them to travel despite their high-priced security personnel and armored vehicles.

NPR: Oversight in Iraq Projects Has Proven Difficult