Continuity mistake: Henry pushes Percy onto the coal tipper twice.
Plot hole: Percy was blamed for being on the coal tipper when it was Arry, Bert, and Henry's fault. None of the three got consequences. Also, why would the workmen tether Percy or even activate the coal tipper when they knew he was an engine?
James and the Red Balloon - S6-E15
Continuity mistake: When Percy arrives at the docks, he is carrying some freight cars. But when Thomas leaves the cars Percy was carrying disappear.
Gordon Takes a Tumble - S6-E17
Continuity mistake: When Gordon leaves the docks, he has his lamp, but in the next scene, it disappears.
Gordon Takes a Tumble - S6-E17
Character mistake: When the narrator says "but the signalman had accidentally left the points switched to the branch line" there is no switch, it's just a bend.
Gordon Takes a Tumble - S6-E17
Continuity mistake: The amount of trucks Gordon is pulling repeatedly change.
Audio problem: Mavis has Derek's horn sound.
Thomas, Percy and the Squeak - S6-E21
Other mistake: When Thomas sees Percy at the washdown, Gordon's front and rear bogie wheels are derailed.
Thomas, Percy and the Squeak - S6-E21
Continuity mistake: When Percy arrives at Brendam, his steam platform is visible and some of the steam from his funnel disappears, indicating a film cut.
Thomas, Percy and the Squeak - S6-E21
Other mistake: When Alicia the mouse is inside Clarabel, she is missing her forepaws.
Thomas, Percy and the Squeak - S6-E21
Visible crew/equipment: When Thomas arrives, his steam platform is visible.
Thomas the Jet Engine - S6-E22
Revealing mistake: After Cranky unloads the jet engine, it is already turned on.
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).
Answer: He was in the water.