I'm don't see how that's supported. Interjected with shots of Dustin Hoffman's character on subway cars, it's unclear whether it's a flashback, dream or fantasy. However, if it was a flashback, it's of a gang of guys barging in on the two of them with the girl getting gang raped while Buck is held down. That's unless you want to believe that half the gang is into gals and the other half are into guys ...