This documentary succeeds triumphantly on so many levels that its full impact doesn’t hit you until you have time to register its aftershocks. If the Army had its way, you would remember Cpl. Pat Tillman as an NFL star (he was a safety for the Arizona Cardinals) who died in combat in Afghanistan in 2004. In fact, Tillman was accidentally killed by his own unit. The Army and the Bush administration preferred to alter the facts and make Tillman, who had grown increasingly disillusioned with the war, the poster boy for military glorification. How such a fraud could be perpetrated and how Tillman’s family uncovered the truth are the subjects of Amir Bar-Lev’s riveting, resonant film, vividly narrated by Josh Brolin. It will get under your skin.