Lister says he once "played pool with planets" in reference to the earlier episode 'White Hole'. However, 'White Hole' ends with time being reversed and Kryten stating that the Red Dwarf crew will have no memory of the episode's events, which means Lister should have no recollection of having played pool with planets.
The triplicator was made to resolve the Dwarfer's supply problems, but anything copied has a lifespan of only one hour, so how could it have solved the supply problem?
In a close up shot of Lister's axe hitting a control panel at the top of a doorway, the blade bends, revealing that it's made of rubber.