Come In, Your Time Is Up - S8-E4
Revealing mistake: In the very first scene Captain Mainwaring and Sergeant Wilson cast multiple shadows despite supposedly being in bright sunshine.
Is There Honey Still for Tea? - S8-E3
Revealing mistake: When Mainwaring first comes into the bank, followed by the workmen with his new door, behind them is the 'high street', actually a painted backdrop. This is normal routine for studio sitcoms, however Mainwaring and the others all cast shadows on the backdrop, revealing it as a studio set.
The Making of Private Pike - S9-E2
Continuity mistake: In this episode, Captain Mainwaring was given a new staff car. However, he already has one from S7 E5, The Captain's Car. What happened to the previous one is never explained, and surely he would not lose all reluctance to accept the job if he already had a staff car?
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.
The Making of Private Pike - S9-E2
Factual error: When Private Pike is on parade and keeps looking at his watch so he is not late for his date at the cinema, the watch is too modern for the period.
Battle of the Giants! - S4-E14
Other mistake: Mainwaring hangs his new cap on a hook on the inside of his office door, the rest of the platoon are having bayonet practice in the hall. Pike is running with the bayonet but misses the dummy and his bayonet goes through the office door and Mainwaring's cap. The bayonet only goes through the cap once, but there are two tears in the cap.
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.
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.