John Hartley Robertson was born in Birmingham, Ala., in 1936, according to the film. He dropped out of school to join the Army and was later chosen to be part of the elite Special Operations Group in Vietnam, MACV-SOG. He was on a war mission when the helicopter crashed in Laos.
"Unclaimed" follows the journey of Tom Faunce, a Michigan man who served two years in Vietnam and made a pledge to uphold his military oath, "leave no man behind." He returns to Vietnam four decades later and discovers a mysterious man who claims to be Robertson.
Faunce works to prove the lost soldier's identity, reuniting him with his family, sister Jean, brother-in-law Henry Holley and their two daughters, Gail and Judy. The filmmakers say the documentary provides a public forum to seek answers from the government in the handling of the case and to have conclusive DNA testing.
Jorgensen, who shot the film last year in Vietnam, Canada and the U.S, told ABCNews.com that the government has never made contact with Jean Robertson-Holley or her family. Just after the film was made, the elder Holleys were critically injured in a car accident and are now in a long-term care facility.
He wonders why the government never called the family when they were interrogating Dang Tan Ngoc, allegedly as far back as 1991 or even 1982. The last such inquiry was in 2009 when the fingerprints were analyzed, according to government reports.
"That's standard operating procedure," he said. "It's simple enough. If someone is perpetrating a hoax or is a fraudster, do your due diligence and warn people, contact the family."
Jorgensen said he spoke to a "representative" of Robertson's American wife, who had since remarried. "They just don't want to be involved," he said. "I was very respectful of that."
"I am absolutely convinced, 100 percent, that the family is convinced it is him," he said of Robertson's sister and brother-in-law. "I never set out to prove his identity. The film was about one Vietnam veteran's journey to help a guy find this man's family. ... Tom's story amazing story of what it means to be human."
As for the director of the GI Film Festival, he says "Unclaimed" is an important film that needs to be screened.
"Whether fact or fiction, "Unclaimed" is a fascinating story about a Vietnam veteran ... who dedicates himself to bringing home someone he believes to be an American GI left behind," said the film festival's Millett.
"Even if he is chasing a myth, we feel his story is compelling and worth telling, as long as it is accompanied by a disclosure to viewers about the controversy surrounding it."