Lassiter makes a list of possible murder suspects out of the members of his reenactment group. With the exception of George Cheslow, who is interviewed by Shawn and Gus, all the names on the list are those of various crew members from the show.
Gus asks Griffin Mahoney if he ever saw Glory (1989). Peter Michael Goetz, who plays Mahoney, played Francis George Shaw in the Civil War film.
After locating the missing bullet, Detectives Lassiter and O'Hara exit to respond to a "439." According to California penal code, 439 refers to misdemeanor insurance fraud.
At 25:53 when Shawn is playing a golf game on the battlefield, he tells the other reenactment actors: "it's not much me as it is Mickelson, he's good." This is a reference to the movie Swingers (1996) when the characters of the movie are playing a hockey game; one of the characters says: "it's not much me as it is Roenick, he's good."
Shawn's line, "That's not a notch ... That's a notch," mimics nearly the same line from "Crocodile Dundee" about a knife. And, less directly, The Simpsons episode in Australia in which they spoofed the same line.