Actor Patrick Scott Lewis, who played Bryan Hartnell in Zodiac, actually had indigestion during one scene. The scene where he holds his stomach was kept in because director David Fincher thought it made his fear seem more realistic. "I just thought that seemed so real, that somebody would actually kinda [have] a moment of indigestion when they see a guy in a black hood and a .45 automatic," Fincher said in the commentary.