The Seven Crystal Balls: Part 2 - S3-E4
Revealing mistake: When Tintin and Haddock break into the shed, they look out of a window to find the intruders getting away. When they look out of the window, Tintin's arm passes through a wooden bar shown near the bottom section of the window. (00:30:20)
The Seven Crystal Balls: Part 2 - S3-E4
Revealing mistake: When the detective is phoning the police about the black sedan, a man sitting at a desk is writing the details. He is writing on four lines of paper, but after writing the first three lines, he is just writing over the third line for a second time and the fourth line of writing suddenly appears on the paper. (00:30:35)
Chosen answer: It is a pill that makes alcohol taste disgusting.