The Broken Ear: Part 2 - S2-E3
Deliberate mistake: When the villains' cuffs are unlocked, only one of the locks get unlocked, yet the cuffs come off both hands. (00:25:10)
Deliberate mistake: Captain Haddock finds out the SOS was a fake so he tells the engine room to increase speed. Just after they increase speed and Tintin says "The people financing the Peary", we can tell the boat isn't moving since the background is entirely still and not moving an inch. (00:14:45)
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