Topsy-Turvy - S3-E10
Other mistake: At the end, after Mary Ann puts the pie down, and Gilligan drinks the juice, he hits the table, flipping the pie into the skipper's face. First, the Skipper starts to wince when Gilligan hits the table, preparing for the gag. Second, the pie tin defies physics by staying exactly in place on the board after the pie leaves it, and after the board bounces once and settles down. Third, Gilligan dips his finger directly into the cream on the Skipper's face, rather than missing a few times.
Topsy-Turvy - S3-E10
Continuity mistake: As the Professor cautions Gilligan about hallucinations, the long table is visible through the door. When the camera is close to the Professor and Skipper, the table is gone.
Topsy-Turvy - S3-E10
Continuity mistake: When Gilligan looks at the papaya tree, the fruit is yellow. When he gets to the tree, the fruit is green.
Topsy-Turvy - S3-E10
Factual error: When looking at the machetes the headhunters had, you can see the molded plastic handles on them. The natives wouldn't have access to such things.
Revealing mistake: In the dream sequence, the boss, E.V.I.L., is bald. You can see the line of the skin wig he has on.
Revealing mistake: After the Skipper throws the attache case in the lagoon, it explodes. Problem is that the lagoon water and the water with the explosion are in two different areas, and where the explosion is, there was no case floating. Just markers floating where the explosive is placed underwater.
Visible crew/equipment: As Gilligan runs along, stuck in the hollow log, the wires holding it up and guiding it are visible toward the top of the shot.
And Then There Were None - S3-E13
Continuity mistake: Whenever one of the castaways falls in the trap and "disappears", there is complete silence when their name is called out, yet when the Skipper falls in (the last of the six), suddenly Gilligan hears all their voices shouting from down below.
Gilligan Goes Gung-Ho - S3-E15
Continuity mistake: In the final scene when the Skipper has Gilligan in jail, he is holding the law book in front of him. The shot changes and he is now holding it by his side.
Revealing mistake: In Gilligan's dream sequence, when the pirate goes to hit his fencing foil, the score mark where the break was supposed to happen is plainly visible, and he's holding it very still for the gag.
The Hunter - S3-E18
Revealing mistake: As Gilligan sits in front of a large boulder, the disguised charge that simulates a bullet strike is easily seen.
The Hunter - S3-E18
Continuity mistake: Gilligan advises Kincaid that there's no game on the island. This contradicts an earlier episode in the same season where the castaways spotted a wild boar roaming the island (episode "Where There's a Will").
The Hunter - S3-E18
Continuity mistake: The target Ramu draws has a small mark in the center. A moment later, the mark is broad and runs top to bottom through the small circle.
The Hunter - S3-E18
Continuity mistake: When Mrs. Howell talks to Ramu, he holds the spear waist high, and beside Lovey. After her question, the spear is suddenly chest high, and aimed about the top of her chest.
Lovey's Secret Admirer - S3-E19
Other mistake: At the end of the episode when Gilligan is using the lie detector he says "I love spinach." The lie detector said it was a lie. But in the episode "Pass the vegetables please" spinach is his favorite vegetable.
Our Vines Have Tender Apes - S3-E20
Audio problem: Towards the end of the episode, the castaways read Tongo's note that he can't take them back with him due to how he behaved with the gorilla. Mr. Howell yells "we won't tell anyone!" followed by other random comments from the others for Tongo to come back. Tongo leaves and as the camera pulls away from the castaways, the same audio repeats itself even though this time doesn't match what anyone is saying.
Gilligan's Personal Magnetism - S3-E21
Continuity mistake: When Gilligan knocks the door off the hut it lands on the Skipper's neck with the life preserver on the top. In the next shot the preserver is on the bottom.
Gilligan's Personal Magnetism - S3-E21
Visible crew/equipment: Toward the end, the group is around the table, talking about Gilligan. Then they see a pear and a bunch of grapes float over to a plate at the head of the table. Skipper goes over and addresses the invisible Gilligan. If you look at the top of the hut, you can see the wires used to make the fruit float. Also, earlier in the hut with Ginger, when Gilligan bit the pear, you can see the wire holding the pear as it shakes after the bite.
Splashdown - S3-E22
Plot hole: Most of the episode focuses on just Gilligan and the Skipper riding the capsule out to sea (although the Howells and the girls attempt to stow away with them at first). However the whole plot changes at the end... suddenly with nobody aboard the capsule, Gilligan tells the Skipper it floated off and Skipper yells at him saying "We could have ALL been on that capsule!" when it suddenly explodes thus saving everybody as if the plot now called for everyone to have been on board. It was still supposed to be Gilligan and Skipper only.
The Second Ginger Grant - S3-E24
Revealing mistake: When "Ginger" (Mary Ann) forgets the words to the song, she asks the maestro, Mr. Howell, to restart the record. Before and after he puts the needle on the beginning, you hear the music, but the turntable isn't moving.
Answer: Bob Denver answered this when he was on a talk show hosted by Pat Sajak. He said they were going to write into an episode where the castaways found all these clothes, but it got too complicated, so he said, they decided, "who cares, it's only a TV show," and forgot about it. So the writers and actors even asked this, they just never bothered to address it.