Visible crew/equipment: When Thomas says to Emily, "Give them back!", studio equipment is visible on the top-right corner of the screen.
Deliberate mistake: Due to the production order, Arthur can be seen at the quarry, but his introduction is 6 episodes later, in "The Spotless Record."
Other mistake: The episode's title in the original PBS Broadcast version is "The Old Iron Bridge" but the bridge was made of wood.
Revealing mistake: When Toby tells the Fat Controller about the broken windmill, his driver's head appears to have been digitally added.
Snow Engine - S7-E14
Other mistake: Before Oliver crashes, no-one appears to be inside his cab in a shot of him passing a crossing.
Audio problem: When Arthur arrives at the lake, he has Spencer's whistle.
Continuity mistake: Because of the production order, Murdoch appears at the sheds, but his introduction is 2 episodes later, in "Peace and Quiet." Spencer also appears at the sheds, but his introduction is 8 episodes later, in "Gordon and Spencer."
Visible crew/equipment: When Thomas says "But I'll be much better when you take these fish away!", a tripod is reflected in the water. (HD widescreen only).
Continuity mistake: Thomas was pushing 4 trucks and a brake van, but when the trucks are laughing at Thomas, there are 2 trucks and a brake van. A truck also gains a face.
Continuity mistake: The fisherman appears out of nowhere when he tells Thomas to enjoy the smell of the fish.
Continuity mistake: When Arthur is waiting for the fat controller to pick him to run the new line, in a wide shot of the sheds, Henry is very close to him, but in a close up of Aurthur, Henry has vanished and Gordon appears one line beside him.
Visible crew/equipment: When Arthur arrives at a station, a shadow of studio equipment is visible on the left.
Continuity mistake: When Murdoch returns to the shed in the last scene, Emily is there too, but in the last two shots, she disappears.
Audio problem: Douglas has Donald's whistle sound when he passes Murdoch.
Fergus Breaks the Rules - S7-E18
Revealing mistake: A wire is under Fergus when he arrives at the smelter's.
Fergus Breaks the Rules - S7-E18
Continuity mistake: When Fergus runs away, his taillamp is on his right side. When he hides in the siding, his lamp is on the left side.
Continuity mistake: When Bulgy is driving on the road next to the rails, Thomas can be seen pulling a train instead of being repaired at the foundry.
Continuity mistake: The mail van moves without a driver.
Audio problem: When Oliver arrives at the station, he has Percy's whistle sound.
Visible crew/equipment: A crew member is visible on the left side of the screen when Skarloey notices the hot air balloon is about to crash.
Answer: Breakdown trains help the engines back on track.