Twenty years after Pat Tillman was mistakenly killed by members of his own platoon emerging from a rocky ravine in Afghanistan, the buddies who took almost all the blame are still frustrated by senior officers' punishment for previously meted out punishment Orders – and for lies – escaped. They told it afterwards – the fratricide.

Last year, ESPN contacted more than 50 people with various ties to the April 22, 2004 incident, including senior military officers, investigators, members of Congress, officials in former President George W. Bush's White House and even the former president himself.

The interviews and a review of 20 years of investigative reports and other documents, including a recent self-published book by a former Delta Force commander, provide a comprehensive look at the decisions that led to the shooting and the mitigation efforts that ensued from the embarrassment the army.

The new findings include:

• The tragedy, which was not reported in any publicly released government investigation, almost became an even worse disaster: An entirely separate group of Rangers was patrolling the same area as Tillman's divided platoon. All three units approached the same hot zone, unaware of each other's presence.

• According to interviews, three officers commanding operations from remote consoles had multiple chances to reconsider potentially deadly decisions but instead overrode platoon commanders on the ground and chose the most dangerous options.

• The long-known cover-up of the event reached the highest ranks of the army. Despite his sworn testimony that he knew nothing about friendly fire until weeks after Tillman's death, General John Abizaid, then head of Central Command, was informed of the likely fratricide in a phone call within 24 hours of the call, according to a senior intelligence official. Under Abizaid's watch, the myth that enemy fire killed Tillman persisted for 35 days.

• A later appointed senior Bush administration official, Army Secretary Pete Geren, told ESPN in his first public comments on the Tillman case since leaving office that the military's deception and failure to report fratricide could be interpreted as a cover-up .

“We found people who were deceptive,” Geren told ESPN. “We found people who knew the truth and looked the other way. And there were several. And you could, if someone wanted, call it a 'cover-up'.”

Read the entire ESPN report here.