Not sure if it's the correct 'part' that I saw.. but it was just an extra minute of Laughing putting on his police uniform and LAUGHING SIR. He didn't really come back to life.. which was good.
you mean this...? http://www.youtube.com/watch?v=jCFdx7XR324 btw, anyone know the song to the video???
yes its only the ending minute that they reshow laughing, there is nothing else of it in the rest of the show. It just talks about how his spirit, once a police, always a police. Its quite ambiguous as to whether he will return in the 4th series or not (as the same character). We will see.