Character mistake: When the group is discovered by Allan, they all take cover behind a rock whilst Allan fires at them. Tintin's position behind the rock would not protect him. Allan is standing directly in front of them and Tintin in taking cover beside a rock that is to the left of him. The area in front of Tintin would still be exposed to Allan's gunfire. (00:26:00)
Continuity mistake: When Allan realises that Rastapopoulos wants Carreidas alive, there is a grenade pin in one of his fingers from the grenade that he just took out. Allan then throws the grenade away, and the pin for the grenade has suddenly vanished. (00:28:55)
Continuity mistake: When the group is reunited with Gino and Skut, Skut is smiling with his mouth open. Tintin walks over to them in the next shot, and Skut's mouth is suddenly closed. (00:33:30)
Other mistake: In order for Rastapopoulos to break into the secret passageway, he places chunks of dynamite around the idol, then lights a fuse for each individual chunk of dynamite, all burning at the same time. The fuse for the dynamite near the middle of the idol is significantly shorter than the fuses for the others. Despite this, it still takes the exact same amount of time for all three to burn down. (00:34:00)
Continuity mistake: At the start, keep an eye on the tape strips over Carreidas' mouth. There is a vertical piece of tape directly over Carreidas' mouth, followed by another piece of tape from the top of his right cheek down to the bottom of his left cheek positioned at a sideways angle, followed by another piece of tape from the top of his left cheek down to the bottom of his right cheek also at a sideways angle. All three strips of tape are meeting with each other at a midway point by his mouth. However, when Haddock says "Come on" to Carreidas and Krollspell when they are under fire later on, the tape strips positioned sideways now meet each other at around Carreidas' left cheek area, further away from his mouth. (00:25:45 - 00:26:40)
Chosen answer: It is a pill that makes alcohol taste disgusting.