Revealing mistake: When Fletcher and Godper are assigned to the work party and they get locked into the church, one of the prisoners, Melvin (the hippy) leans against one of the 'stone' pillars of the church, causing it to wobble.
Revealing mistake: During the riot scene, the canteen walls wobble. This is most noticeable when a prisoner is trying to pull the notice board off the wall.
No Way Out - S2-E7
Revealing mistake: When Fletch falls through the hole in the yard, this is obviously performed by a stunt double as he has a different hairstyle to Ronnie Barker.
