Tillman 

Mistakes, yes, coverup, no.  So said former Defense Secretary Donald Rumsfeld in a congressional hearing into the death of Pat Tillman.  Tillman was an NFL player who became an Army Ranger after 9-11.  He was killed by friendly fire in Afghanistan in 2004.  The Army originally said he was killed by enemy fire.  Rumsfeld cited numerous errors, but said he has seen no evidence of a coverup in the Tillman case. 

Rumsfeld testified along with retired general Richard Myers, former chairman of the Joint Chiefs, and John Abazaid, former chief of U.S. Central Command.  Rumsfeld also testified that he cannot recall exactly when he became aware of the discrepancy in reports about how Tillman died.