Cigars of the Pharaoh: Part 1 - S1-E6
Revealing mistake: On the boat, Tintin chases after a paper. There is a shot of a man being handed a drink and the paper continues to blow away. Keep an eye on the paper and you will see it disappears before it reaches the end of the screen. (00:01:35)
Red Rackham's Treasure - S1-E5
Revealing mistake: In the shot where Tintin drives past the Unicorn and a shark appears, a white speck is visible to the left of screen. It disappears from shot when the shark arrives in shot. (00:14:05)
Chosen answer: It is a pill that makes alcohol taste disgusting.