When Regan watches a TV documentary about Professor Busby, an on-screen caption identifies him as "Professor William Busby" but the reporter refers to him as "Frederick Busby". Also, when Busby makes a phone call later on in the episode, he says "It's Freddie".
During the chase at the end, the road is quite clearly a test track or motor racing circuit. It is far too wide for even a British 'A' class road and is devoid of lane markings, or markings of any sort.
After being shot and killed Harry Grieve can be seen breathing laying on the floor as the Sweneeys car pulls up,
When Morecambe and Wise are doing their ventriloquist routine, the camera tracks behind the audience. Despite the sound of uproarious laughter from them, not one of them moves a muscle: it looks as if the laughter may have been dubbed on afterwards.
After the vehicle is retrieved from the lake the vehicle is obviously wet but Carter once inside sits down on a what will be a wet seat, why would he.