Continuity mistake: At the beginning, Edward is pulling 5 cattle trucks. When he approaches the cows, he is pulling 4 cattle trucks.
Continuity mistake: Gordon's express train has 1 composite coach and 2 brake coaches when he passes through Wellsworth station. When he crosses the viaduct, he has 2 composite coaches and 1 brake coach.
Continuity mistake: Gordon can be seen next to Edward when Edward says "two big engines afraid of a cow?", but Gordon should have been on the turntable.
Thomas, Percy and the Coal - S2-E1
Continuity mistake: When Thomas is being covered in coal, he is dirty in some shots, but in other shots he is clean.
Continuity mistake: When Edward stops at the station, a close up of his whistle shows the sky is sunset dark, but when he arrives, it's bright daylight.
Continuity mistake: When Bill and Ben notice their trucks are gone, there are guards in front of them, two shots later, there is no sign of the guards.
Answer: He was in the water.