Other mistake: When James crashes into the tar wagons, Sticky Tac can be seen on his tender.
Continuity mistake: In a close up of the tar wagons before James crashes into them, James disappears.
Visible crew/equipment: When James crashes into the tar wagons, a crew member's finger can be seen pushing him.
Character mistake: The narrator says that James ran into two tar wagons, but he ran into four. Two is the amount of tar wagons that derailed.
Continuity mistake: James leaves Elsbridge Station with the brake coach at the rear. When James arrives at Knapford Station, the brake coach is in the middle.
Other mistake: James passes a green signal, but there are tar wagons ahead.
Answer: He was in the water.