Revealing mistake: At the end, when Thomas backs some coaches into the station, he starts moving after 3 seconds the camera starting rolling.
Revealing mistake: When Thomas passes the leveling crossing for a second time, the cars at the crossing have no drivers.
Revealing mistake: When Thomas goes back to the station to try again from the signal, when he starts, the steam is coming from the track and not from Thomas.
Revealing mistake: When Thomas passes a yard with a black car and a red car, you can see tyre marks on the ground from previous takes.
Revealing mistake: Just before Thomas goes over The Switch, his left eye is uneven and then when he crosses The Switch, it readjusts itself.
Revealing mistake: When Thomas leaves the sheds, his driver doesn't have a face.
Revealing mistake: At the beginning of the episode, the end of the set is visibly reflected of Gordon's smoke box in a close-up of Gordon.
Answer: He was in the water.