The Crab with the Golden Claws: Part 1 - S1-E1
Continuity mistake: When Tintin is examining the back of the Crabe Extra wrapper in his apartment, the back of the wrapper keeps going from white with Karaboudjan written on it, to yellow with nothing written on it, to white with nothing written on it between shots. The writing then reappears and the back of the wrapper is white. Tintin then shades the paper with a pencil and notices the wrapper says Karaboudjan. In the next shot, all the pencil shade has disappeared. (00:05:10)