Plot hole: After being spared, Medieval Sandy announced that she will help in the defeat of medieval Plankton. How did she know what they were planning?
Patrick SmartPants/SquidBob TentaclePants - S4-E8
Plot hole: In 'Patrick SmartPants' Patrick lost the top of his head after falling off a cliff, but Spongebob put it back on. Suddenly Patrick's intelligence skyrocketed, but wanted to return to his former self in the end of the episode. To do this he re-enacted his fall, but it was unsuccessful. They eventually figured out that Spongebob had in fact not put on Patrick's head, but a 'brain collar'. How did Patrick posses his memories throughout the 'intelligent phase' despite not having his own head (and brain)?
Plot hole: In "Once Bitten", Mr. Krabs never unlocks the doors to the Krusty Krab, but at the end of the episode, Squidward enters with no problem.
Suggested correction: Maybe Squidward has a key to the Krusty Krab that Mr. Krabs doesn't know about.
He could still have a key, but we don't see it.
Whether or not Squidward owns a key to the Krusty Krab is beyond the point of the mistake here. The point is that Squidward is able to walk into the Krusty Krab despite the doors being locked, and he doesn't use a key or anything else to unlock them. He just pushes them open.
Maybe the doors were not locked properly.
