In a seventh season episode the The Big Bang Theory titled The Raiders Minimization, Amy pointed out to Sheldon a “glaring story problem” in Raiders of the Lost Ark (the best action movie in the history of ever): Indiana Jones’ actions in the movie do not affect the outcome of the film. Suppose that he is not involved in the story, the Nazis would have dug out the ark anyway, they will open it and will still be dead from looking at the Ark.
Howard later argues that the Nazis are digging in the wrong place and without Indy they would not have found the Ark. However, Leonard quickly counters correctly that the Nazis are only digging in the wrong place because Indy have the medallion. If Indy is not in the story, the Nazis would have taken the medallion from Marion (and possibly kill her) and they will be digging in the right place and found the Ark. There is another argument at the end of the episode but it is irrelevant. For me, Indy’s failure to bring the Ark to the museum does not constitute a solution to the story problem. Furthermore, the film is not ruined simply because of that!
Before the episode was aired, I have read about this story problem before somewhere else, although I can not point exactly where. It is a very sound argument and in fact it is correct. Indiana Jones plays no role in the outcome of the story.
I am not really sure whether George Lucas, Philip Kaufman, and Lawrence Kasdan were aware of this problem when they put the story down, but the problem can be explained—but not solved—by being aware that the Ark is a MacGuffin. A MacGuffin motivates the characters in the story to pursue it and it moves the story forward. What the nature of the MacGuffin actually is are seldom explained in the film. It is usually only described by the characters in the vaguest term possible, but enough to spark the imagination of the audience. The audience are to be made understand about the importance of the MacGuffin and what is at stake, and we understand the motivations of the characters.
Thus the point of the film with a MacGuffin as a narrative device is to see how the characters interact with each other in order to obtain it. From these interactions (hopefully) we can get emotionally involved and learn something about them. Hence Indy plays no role in the outcome of the film is not really a problem at all as long as the story unfold itself as it motivated by the chase for the MacGuffin.
Nevertheless, the story problem can only be resolved by considering other materials outside the film: A deleted scene and the novelization of the film by Campbell Black (haven’t read this in a very long time).
In one of the deleted scenes from the script of Raiders, there are additional dialogues at Imam‘s house (Imam is the Egyptian scholar who translate the markings on the medallion. He is not named in the film but his name is written in the credit), in which Imam explains the danger of the Ark: If you touch the Ark, you will die. If you look at the Ark when it is opened, you will die. This scene explains why Indy knows not to look at the Ark when it is finally opened on the secret Nazi island, thus saving his and Marion’s face from melting. Notice as well that in the Well of the Souls, Indy stopped Sallah from touching the Ark. He remembers Imam’s warning and remind Sallah of it. The Ark is then moved by using poles slipped through rings on the sides of the Ark. Throughout the rest of the film nobody touches the Ark until the finale.
This dialogue was never filmed but it exists in the script. While not showing this dialogue in the film creates a plot hole (how does Indy knows not to look at the Ark?), it is understandable not to warn Indy and the audience about the dangers of the Ark: To keep the tensions and to keep the curiosity of the audience until the end. No one knew what is going to happen if we open it, and the film would certainly be ruined should the dangers are exposed early on.
This unfilmed additional dialogue is the solution of the story problem, assuming that the warnings about the danger of the Ark are also written in the medallion, on the same side as the order to take one Kadam to honor the Hebrew god (in short, the side not copied by the Nazis). The Nazis open the Ark and die as a result because they do not know about the warnings. They do not know it because Indy has the medallion. If Indy is not present in the story, they would then have the medallion and thus aware of the warning. Belloq might not want to open it, convinced Dietrich as well, and take the Ark to Berlin. Hitler might not want to open it as well and orders for the Ark to be stored in a secret warehouse for safekeeping. Well… this outcome of the story is a bit similar except that the warehouse is in Germany instead of in the US, but… small details there. Simply put: Indy’s presence do change the outcome of the story. By removing the medallion from the Nazis, Indy deprives them of the knowledge about the dangers of the Ark.
Of course this solution holds only if we want to accept materials outside the film as canon.