Continuity mistake: In War Dance (4-2) the verger Mr. Yateman's wife's Christian name is Anthea. In Everybody's Trucking (8-1) it is Beryl, and in Knights of Madness (10-3) she is called Tracy.
Other mistake: The Church Hall got through an impossibly large number of different pianos, especially considering the fact that there was a war on.
Continuity mistake: (Colour episodes only) In the section of the closing credits that features the main cast members marching, the sky colour and positions of the shadows on the ground change depending on the actor being featured at the time (the sky is blue when Arthur Lowe, John Laurie and Ian Lavender are seen, but it is grey when John Le Mesurier, Clive Dunn, James Beck and Arnold Ridley feature). This is more obvious on episodes that have had colour restoration undertaken.
Visible crew/equipment: "Resisting the aggressor down the ages" (Christmas night with the stars special episode) Just after Jones bangs the gong at the wrong time and says "that was a mistake, I'm sorry" there is a boom mike shadow on Mainwaring's union jack waistcoat.
The Armoured Might of Lance Corporal Jones - S3-E1
Visible crew/equipment: As Hodges is gathering a crowd together to witness the demonstration of how the van can be used as an ambulance, a boom mike can be seen briefly at the top of the screen.
Continuity mistake: The platoon's rifles have no fore sight at various times in this episode, at other times they are fitted. Most noticeable on the railway platform and the march to camp (missing), but when they arrive at the camp, all the fore sights are on. They are missing during the outdoor training scenes - and they are missing from the credits at the end of every episode when the platoon members are shown in close up (these shots were from this episode). (00:09:00)
Other mistake: When the train stops Godfrey gets off to relieve himself but when he is climbing back in to the carriage the train appears to be already moving at speed because the background projection started moving too early.
Other mistake: Walker is attempting to steal items from the farm but appears on the training activity with the other troops at the same time.
Continuity mistake: The Verger Mr Yeatman's first name is Maurice, but in this episode it is Henry.
Revealing mistake: When Frazer is attempting to get the chocolate out of the crane machine, he tells Mainwaring to keep quiet. When he does this, he takes his hands of the machine, and it picks up the chocolate on its own, without anyone controlling it.
Visible crew/equipment: When Pike returns to the arcade to tell the platoon that he has lost the boat you can see the shadow of the boom mike in Walkers face.
Visible crew/equipment: Towards the end of the episode where Godfrey goes back into the smoke filled hut to rescue Captain Mainwaring, the shadow of the camera is visible on the hut.
Don't Forget the Diver - S4-E2
Factual error: While Capt. Square is looking through his binoculars at what he thinks is Mainwaring's platoon marching with their rifles, a 1960's Bedford lorry drives past on the road behind them.
Factual error: In several scenes during the cricket match while the Walmington platoon are bowling/fielding, cars can be seen on the road behind the cricket ground that were made well after the 1940s.
Audio problem: Jonesy is playing the organ. A pigeon 'flies' out the top of the organ and lands on the keys, so Jonesy picks it up and moves it, taking both his hands off the keys. Yet the music plays on.
The King Was in His Counting House - S5-E7
Factual error: Captain Mainwaring is transferring money from his bank to another branch after it has been bombed. He has the money in a basket and is transporting it on a horse and cart when some of the money starts blowing out of the basket. Pike, Wilson, Walker, and Jones are riding bicycles behind him. They stop to pick up the money and just before Jones tells Pike to ride after Mainwaring to tell him about the money, you can see a silver car parked on the left hand grass verge in the direction Mainwaring is heading. This car was obviously made long after World War Two finished.
Continuity mistake: When the second bottle thrown by Pike lands on the floor, the glass from the first bottle has all disappeared.
Revealing mistake: When the knight moves back and forth during the clock mechanism's operation, as he swings his sword, a blue pullover sleeve is visible beneath his armour, revealing that he is an actor in costume and not an automaton.
Revealing mistake: The lights in the café are not working, despite the room being brightly-lit from above (i.e. the brightness cannot be attributed to sunlight entering through the window).
Other mistake: Wilson picks up the empty tablet bottle, but we hear the tablets rattling inside. Wilson then says 'it's empty, sir.'
Answer: The show is a comedy, this was played for comedic effect and to show that in times of extreme fear, in this case about to be crushed by a steam train, the men had an adrenaline surge strong enough to pedal fast enough.