Explorers on the Moon: Part 1 - S3-E11
Other mistake: Wolff is explaining that if the motor is shut off again, the magnetic sole boots they are wearing will stop them from floating. Whilst he is explaining this, he is placing the boot straps over the Velcro. The first strap he places is only partially on, but a few frames after, a blip occurs in the animation, and the strap is suddenly entirely over the Velcro. The same happens with the second strap as well. (00:08:00)
Prisoners of the Sun: Part 1 - S3-E5
Other mistake: After the man on the ship tells Tintin that Calculus' punishment is death, he yells for Alonzo, and Tintin then punches him. When the man is punched, it is apparent that Tintin's fist never even enters the frame. There appears to be a flash effect indicating that he had been punched, but Tintin's fist is never shown hitting him. (00:07:05)
Explorers on the Moon: Part 1 - S3-E11
Other mistake: Haddock is lowering crates onto the moon and looks over to see Thomson and Thompson, whilst they are heard playing around off-screen. In this shot, Haddock's antenna cannot be seen through his helmet, even though the helmet should be transparent. (00:20:40)
Prisoners of the Sun: Part 1 - S3-E5
Other mistake: After Tintin unties Haddock, he jumps up, taking off his poncho. He then throws the poncho into the air, but it is never seen again, nor is it ever shown falling onto the ground. (00:18:20)
The Red Sea Sharks: Part 2 - S3-E2
Other mistake: After the recap from the previous episode, Tintin, Haddock and Snowy are on a boat. Tintin is shown pulling on a rope to attach a sail. The amount of rope shown near the ground is never seen extending. It remains the same length even when Tintin is pulling on it. (00:25:05)
The Red Sea Sharks: Part 2 - S3-E2
Other mistake: Tintin and Haddock discover that part of the ship is on fire and discover a group of people hiding out under the deck. Haddock then lowers a ladder, down below the deck, so that the others can climb out, but even after every single person down below decks climbs out, the fire has not extended or grown further in any way, even after the time spent letting all the people out. (00:34:50)
The Seven Crystal Balls: Part 1 - S3-E3
Other mistake: When Sanders finishes the translation, he puts a full stop at the end of the sentence, but there's no sign of the full stop on the paper.
Chosen answer: It is a pill that makes alcohol taste disgusting.