The Secret of the Unicorn: Part 1 - S1-E3
Revealing mistake: Francis Haddock lowers himself from the ropes to the lifeboat below. He steps foot inside the boat, but the bottom of his legs and his feet are still perfectly visible when they should have been covered up by the boat. This error in the animation makes the boat appear as if the boat is missing one of its sides. (00:18:50)
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