The Sherriff knocks Robin's sword away and is about to kill him. Clara throws a sheet over his head, blinding him so that Robin can grab his sword and cut the Sherriff's head off, which rolls away. The Sherriff's body then gets back up and grabs Clara, while the Sherriff's head tells how the spaceship landed on him - revealing by this that *he* is the titular Robot of Sherwood! He then threatens to have his body kill Clara if they don't give him back, so Robin throws the head to the body, which releases Clara in order to catch it. It then reattaches the head, and Robin says something about this giving him a sporting chance. They then resume their fight, with the ropes.
Of course, aside from meaning the title is now meaningless, this edit also means everyone will have seen the *human* Sherriff get killed, rather than a robot Sherriff get melted.