Revealing mistake: When Thomas collects Rocky, the points are set against him. This also happens when Percy enters the siding.
Visible crew/equipment: When Gordon, Thomas and the express round the bend, a camera tripod is visible on the left side of the screen.
Visible crew/equipment: In a close-up of Toby, you can see a hand reflected in his left window (viewer's right).
Wrong Road - S2-E22
Character mistake: The narrator refers to the brake coach as the guard's van.
Answer: He was in the water.