Continuity mistake: In the scene where Stallone gets hit by the UFC fighter, he doesn't see the hit coming because he gets hit from his right side. Later on, when driving his girlfriend home from the restaurant, he is still blind in his right eye and doesn't see the car coming from the right. However, during the Grudge Match, he is suddenly blind in his left eye.
Henry 'Razor' Sharp: Listen, uh, your thing. Turn it down.
Lightning: Oh, the hearing aid. Goddamn thing drives me crazy, feels like R2-freaking-D2.