The Crab with the Golden Claws: Part 1 - S1-E1
Plot hole: Whilst Allan is searching the decks below for Tintin, a crew member is keeping watch of Captain Haddock in his quarters. Tintin secretly reveals to Haddock that he is hiding underneath his bed, without letting the crew member notice him and Haddock then looks towards him. The crew member was watching Haddock the entire time, so how does he not notice Haddock looking toward Tintin? (00:18:20)