In the film, Sgt. Jack Lupino is depicted as a United States Marine Corp Sargent. However, when Max is watching an interview with Lupino it shows him wearing either a Gunnery Sargent or Master Sargent chevrons. Not only that, but the chevrons happen to be upside down. No US Marine would ever make a mistake like that.
At one point during the movie, Max visits a storage yard. The name of this yard is "Gognitti Storage". This is a reference to Vinnie Gognitti, who was an important character in the video game series.