The Castafiore Emerald: Part 2 - S3-E8
Continuity mistake: When Castafiore is complaining about the stairs not being fixed, the first shot of her shows nothing on the torso section of the dress she is wearing, but when the shot is on her next, a small design has suddenly appeared on the chest area of her dress. (00:24:55)
Chosen answer: If Hector was seriously intent on removing King Ottokar's scepter from the glass cage holding it and launching it through the window with the camera, then Hector would have been forced to knock out the two guards so they would not have interfered with Hector's plan as soon as he removed the scepter from the glass. As for Hector, himself, was explained when Tintin was explaining how Hector stole the scepter. Tintin placed a twig inside the camera and it launched out of the camera. Hector would have placed the scepter inside of the camera, and would have been knocked unconscious due to the spring effect created when the scepter had been launched.
Casual Person