Visible crew/equipment: In the first shot of our heroes being given their assignment, something, presumably a crew member, can be seen intruding into the frame to the right of Barbara Windsor and casting a shadow on the desk. (00:11:50)
Revealing mistake: When our heroes are on the conveyor belt which carries the rocks towards the spinning saw blades, the rocks which get cut in two are seen to be cut before they reach the blades. (01:20:45)
Revealing mistake: When our heroes are on the conveyor belt heading towards the saw blades, it's obvious that the conveyor belt on the other side of the blades is just a painted backdrop. (01:20:45)
Other mistake: When our heroes are on the conveyor belt in the rock-processing plant, none of the rocks are larger than two feet in size - especially having gone past a set of spinning saw blades - and yet they get sprayed by two steam nozzles, the highest of which is about six feet in the air, and the lowest is about four feet in the air. Clearly neither of these nozzles would have any practical use. (01:21:10)
Continuity mistake: When Desmond Simkins and the rest of the gang emerge from the lift at the Chief's office, you can see that there is a dust mark on the left side of Desmond's suit, but when we see a close-up of him in the next shot, the dust mark has gone.
Visible crew/equipment: At the beginning of the film when the trainee agents are being briefed in the chief's office, the camera lights are reflected in the glass cabinet.
Revealing mistake: When Charles Hawtrey picks up the formula in the Street of a Thousand Artisans, you can see that the cobbled street on which it has fallen is made of rubber as it bends with the pressure of his hand.
Continuity mistake: When Bernard Cribbins points out the cherries in their champagne cocktails in the Café Mozart, both his and Barbara Windsor's cherry sticks change position between shots.
Continuity mistake: When the four agents are trying to escape the STENCH Headquarters, Crump bumps into Simkins and he drops one of the two spools of tape. But when we see the group just a few seconds later, all of the tape has been collected up and both spools are in Simkins' hands.
Continuity mistake: Simkins finds the girl in his wardrobe in his room on the train. There are two jackets hanging up in the right hand side of the wardrobe - when he opens the wardrobe door again immediately the girl has gone but the jackets are still there. Harold Crump then enters Simkins' room - the wardrobe door is still open with no jackets visible, but when Simkins closes the wardrobe door there is only one jacket hanging up in there.
Continuity mistake: When Desmond and Charlie lure the doorman from the fun house, Desmond hits him with a copper pot and his fez falls off and lands in the middle of the doorway. In the next shot, from inside the building, the fez is nowhere to be seen.
