Trivia: As Sallah leaves Indiana's place, he can be heard singing the same song that he sings in Raiders of the Lost Ark (when Marion gives him a thank-you kiss).
Trivia: When we see Indy watching television in his apartment, there is a painting on the wall. This is a painting of the magical "Leap of Faith" bridge, which was seen in the climax of Indiana Jones and the Last Crusade (1989).
Trivia: SPOILER: The movie reveals that Indy and Marion's son, Mutt, was killed while serving in Vietnam. Shia LeBeouf, who played Mutt in Indiana Jones and the Kingdom of the Crystal Skull, has been vocal about his dissatisfaction with his performance in the film, much to the chagrin of both Harrison Ford and Steven Spielberg. That, coupled with the negative fan reception of his character/performance, are likely the reasons that LeBeouf did not return for this film.
Trivia: When Indy pulls the Nazi guard off the edge of the train, the guard lets out a Wilhelm scream.
Trivia: This is the first movie in the Indiana Jones series not directed by Steven Spielberg, nor with a story written by George Lucas.
Answer: It was never explained and seems impossible that anyone could survive such an impact. My own thought was the scene was deliberately exaggerated to appear as if Voller was killed in order to fool and then surprise the audience when he later turns up alive. I also thought it looked as if he hadn't aged. Voller may have been much younger than Indy, possibly as much as 25-30 years. When Voller reappears in the 1960s, he looks more like actor Mads Mikkelsen's actual age. The film should have made him look younger at the beginning. There's a lot of "suspension of disbelief" here.
raywest ★