Continuity mistake: The Cat brings down the town sign by shooting the right hand side of it. Seconds later, when they pick Kryten up, the sign is hanging in front of the Livery building, which would only have been possible if he'd shot the left hand side.
Revealing mistake: When Rimmer stands up from underneath the table, just before he says, "Thanks for your support" to Lister, listen very carefully and you can hear the stunt director saying "Action!" backwards. This shot was the splice point between the reversed and the regular footage. (I know this mistake is listed as being in the 'backwards version' on the DVD, but it is in the regular broadcast version too - you just have to listen harder for it.)
Revealing mistake: At the start of the episode, we see Lister in black and white talking to Loretta. Then we cut back to what's really happening, he is playing on the AR console. Look at the door behind him, you can see Kryten's hand sticking out in the doorway. He is supposed to rush in and start talking, but you can see him waiting off camera to be told when to enter the room.