In a scene where the robbers are climbing into the police station back yard, the ladder they are using does not reach the top of the wall. However, when they drop down on the other side, the top of the ladder is at least 2 feet above the wall. Similarly when George first spies the ladder against the girl's window, it reaches above the window ledge, but when the young man climbs it when the couple are eloping, it does not reach to the window.
During the bedroom scene when they first get the telescope to look into the police station, there is a bedside table next to Dick Emery. In the course of several shots of the table a booklet appears-disappears-reappears and the clock goes back in time.
The wire to pull the harpoon out of the harpoon-gun can be clearly seen in the shot just before the first one is fired into the tree.
In a scene where the robbers are climbing into the police station back yard, the ladder they are using is a double ladder which not extended. When viewed from within the police yard, the ladder is extended.