Plot hole: When Duck and Diesel leave the shed, Diesel follows Duck instantly, but the tracks they are on both lead to the turntable. As they are on different tracks to each other, it would be impossible for Diesel to follow Duck that quickly as the turntable could only be set to one track at a time.
Character mistake: The narrator says, "some trucks were left behind", but only 1 truck was left behind.
Thomas and the Missing Christmas Tree - S2-E26
Visible crew/equipment: In the scene of Donald and Douglas going out of the yard, a camera tripod can be seen in the top left corner.
Thomas, Percy and the Coal - S2-E1
Visible crew/equipment: In the restored version, studio equipment can be seen when Toby pulls Annie and Clarabel and at the water tower near Tidmouth Station (at the top of the screen in both scenes).
Thomas and the Missing Christmas Tree - S2-E26
Other mistake: In the shot of Donald, (or Douglas) Gordon and Henry, Donald has Edward's face.
Thomas Comes to Breakfast - S2-E18
Other mistake: The narrator said Thomas was feeling conceited, but Thomas had his sad face mask on instead.
Revealing mistake: When Duck goes off to fetch Gordon's coaches following his chat with Diesel, the device beneath the tracks used to produce steam continues to smoke long after Duck has left.
Revealing mistake: In a close up of Percy's driver, he is in Henry's cab.
Revealing mistake: When Percy is at the "backing" signal, his cylinder is sagging.
Audio problem: Edward has Thomas' whistle sound when he first sees Trevor and when he approaches Wellsworth Station.
Revealing mistake: When Edward is at the last station, his whistle is crooked.
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.
Revealing mistake: After Gordon stops on the bridge for the cow, his wheels keep moving for 3 seconds.
Revealing mistake: When Percy stops on the bridge, white glue is on his middle lamp iron.
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.
Revealing mistake: Edward has wonky eyes in some scenes.
Thomas, Percy and the Coal - S2-E1
Revealing mistake: In some shots of Thomas and Percy, both engines have wonky eyes.
Thomas, Percy and the Coal - S2-E1
Revealing mistake: When Toby pulls Annie and Clarabel, the latter coach has a loose roof.
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.
Answer: Breakdown trains help the engines back on track.