According to director Mel Gibson, Desmond T. Doss's son, Desmond Jr, attended the screening and was moved to tears by Andrew Garfield's accurate portrayal of his dad.
Hal B. Wallis had previously tried to buy this story from Desmond T. Doss in the 1950s, and hoped that Audie Murphy would star. Doss didn't want his story turned into a typical Hollywood movie.
Mel Gibson said that the battle scenes were influenced by nightmares he had during his childhood, when his father Hutton Gibson, a World War II veteran who served in Guadalcanal in the Pacific theater, described the horrors he witnessed as bedtime stories.
With the exception of Vince Vaughn, the rest of the major actors and the supporting cast were born or raised in England or Australia. The film had a relatively low budget, and the production needed a majority-Australian cast to qualify for Australian government subsidies.
The trailer states that Desmond T. Doss was the only soldier to serve in a front line capacity without carrying a weapon. In World War II, Korea, and Vietnam, the military gave several Seventh-Day Adventists the status 1A-O - willing to serve but not to carry a weapon in combat. Numerous Quakers volunteered for service in World War I.
Mel Gibson: During the final assault after Desmond T. Doss is injured and carried in the new hanging platform to be transferred down, several soldiers assist. One of them is Director Mel Gibson.