Whatever one’s feelings about Bush Administration policy in Afghanistan and Iraq, its handling of the death of Pat Tillman was certainly a particularly crass element in its effort to sell the conflict to the American public. As Amir Bar-Lev’s documentary makes clear, the unhappy episode not only reveals the attempt of the military to cover up a tragic error but of hawkish officials to exploit it for political gain. “The Tillman Story” is yet another cautionary tale, as if more were needed, about why it’s not wise to be too trusting of governmental pronouncements.

Tillman, of course, was a professional football player who abruptly gave up his lucrative contract with the Arizona Cardinals in 2002 to enlist, along with his brother Kevin, in the Army Rangers. He declined to discuss his motives publicly, but Secretary of Defense Rumsfeld, among others, recognized the value of him as a poster boy for patriotism. And when he was killed in Afghanistan, it was quickly announced that he had died heroically to save his comrades during a Taliban attack on their patrol, and his memorial service was used to promote support for the war. Tillman was being turned into a plaster saint and useful political icon.

But his family would have none of it. They were hardly your typical American clan to begin with, either in lifestyle or beliefs, and the image of Pat as some super-hawk was far wide of the mark. He had dismissed the Iraq invasion as illegal even as he participated in it, but when given the chance to opt out of completing his three-year hitch, had declined and returned to the field. Now his parents and younger brother were determined to find out the truth about his death, and the story quickly put forward by the military brass and trumpeted by the administration soon began to unravel as some of Tillman’s fellow soldiers disputed it (and suffered professionally as a result). The army was eventually forced to admit that Tillman had probably been killed by friendly fire, and ultimately an investigation placed blame for the entire cover-up on a mid-level general who’d been ordered to announce the original explanation. Later congressional hearings, called in response to continuing family pressure, saw higher-ups (including Rumsfeld) resort to the old standby excuses of misdirected messages and faulty memories. As so often happened, those who most demanded responsibility from others refused to accept any themselves.

“The Tillman Story” is unabashedly one-sided. Its point of view is that of the Tillman family, and it treats the army brass as more interested in protecting their own positions—and the institution they head—than in doing justice to a man who lost his life in a military foul-up and the loved ones he left behind. It even calls upon a retired Special Ops soldier to explain how the military establishment routinely uses tools of obfuscation to conceal blunders like Tillman’s death. The film shows even less respect—if that’s possible—for the politicians whose self-interested, and arguably indefensible, policies the generals must try loyally to carry out.

Bar-Lev’s picture doesn’t really reveal anything new about the Tillman case—the lies about his death, the crass exploitation of it for political gain, and the sad realization that those at the highest levels will escape punishment are all old news. But by presenting the horrifying evidence in such detail, it performs a real public service. And just as important, it captures Tillman’s complexity; this was a intelligent, talented, rambunctious man with an intensely personal code of honor that puts the principles of those who sent him into harm’s way to shame. It also captures the admirable character of the family that raised him and refused to be lied to about his sacrifice.

So though this is a film that will infuriate you from an institutional perspective, it’s also strangely uplifting from a personal one.