The Israeli Military Intelligence Directorate does indeed have a devil's advocate office to explore alternative assumptions and worst-case scenarios so intelligence assessments doesn't fall victim to "group think," but it is not called the 10th Man Doctrine.
Brad Pitt said of his involvement in the film, "This whole thing started because I just wanted to do a film that my boys could see before they turned 18 - one that they would like, anyways. And they love a zombie."
Before attempting to enter B-Wing, Lane and Segen are given the option of an axe or a baseball bat and are told "there are merits to each." This is an in-joke reference to a section of Max Brooks' "Zombie Survival Guide" (the book that preceded "World War Z") which discussed the best weapons to use when fighting zombies. The book considers both options superior to the gun, which Segen also takes as a backup.
Marc Forster states that he prefers the extended, unrated cut of the film. For him it's not just about the additional blood and gore, it's about the overall intensity compared to the PG-13-rated version. Forster says that although he's proud of the theatrical version, he felt a bit "handcuffed" when he was trying to deliver the toned-down PG-13-rated version.