In the film, the man claiming to be Robertson had an enamel isotope test done on one of his molars to learn more about his background. One of his teeth was removed and sent to an expert back in the U.S. for further examination. At the time, Jorgensen and Faunce hoped that the results of this test would add more validity to the man’s claims.
Lesley Chesson from IsoForensics, Inc. was the expert who analyzed the tooth. After looking into the chemicals found on it, she concluded it was very likely that the man was raised in the United States. While he certainly wasn’t Robertson, there was still the possibility that he genuinely was an American veteran left behind after the war.