Continuity mistake: When the virus starts to eat the potatoes, Rimmer picks them up from the pile just below eye level. In the wide shot it shows the potatoes are just below waist level and Rimmer would have had to lean much further away from where he was standing to get the potatoes from that height.
Revealing mistake: In the scene where Kochanski, the Cat, and Kryten first discover the time wand, there are a group of Canaries who are frozen in time from its effects. In the first shot of these people, the woman on the far right of the screen blinks her eyes. (Confirmed on DVD commentary).