The Crab with the Golden Claws: Part 2 - S1-E2
Other mistake: The newspaper article that features Tintin and Captain Haddock at the end of the episode is a flipped shot, as shown by the text that has been reversed. (00:43:35)
Continuity mistake: While the family is eating at the table Ferguson is talking the camera is on Ferguson and Marshall. Marshall has a fork and syrup in his hands, the next shot he is now holding a cup and the syrup is near Janet.
Other mistake: A time card reads 6,000,002 BC, when it should've read "60,000,002 BC". (00:07:12)
Continuity mistake: When Marshall first finds Trip's letter, he holds it from the left side. In the close-up, he's holding it from the right side. (00:02:10)
Visible crew/equipment: At the very end of the episode, the top of the set and crew lights are visible on the top on the screen.