Brad Pitt broke his arm on set

While filming a rain-soaked chase scene in Los Angeles with Kevin Spacey, Brad Pitt suffered a serious injury when he slipped and shattered a car window with his arm. The accident left him with a severed tendon and a deep cut down to the bone.

After taking time off to recover, Pitt returned to set wearing a cast, which initially created a continuity issue for director David Fincher.

To resolve it, Fincher decided to incorporate the injury into the script.