Survival of the Idiots / Dumped - S2-E8
Other mistake: Survival of the Idiots: When SpongeBob and Patrick first try to escape the tree dome, SpongeBob tries to open the door, then says that the door is slippery and frozen shut. SpongeBob's reflection is shown in the ice on the door, but it is not backwards; note the holes on his face. (00:08:43)