Audio problem: At the end of the show when Alice is blowing the whistle, the whole family comes to the top of the stairs. Mike says "Alice, it's 6 o'clock in the morning" Watch his mouth. It looks as though he curses and the (curse) word was dubbed out.
The Spanish Inquisition - S2-E2
Revealing mistake: At the very end when The Spanish Inquisition bursts into the courtroom, you can see that Biggles is not played by Terry Jones (as he is playing the accused judge in the court sketch).
Continuity mistake: Scooby finds a clump of ape hair stuck in the wine cask. It cuts to the gang, then back to the cask as they walk up and suddenly the clump of hair is twice as thick. (00:16:45)
Visible crew/equipment: In the opening scene, when Inspector Blake informs Stan and Arthur that the 10:45 bus has arrived, the camera pans over to the door of the bus where another cameraman's shadow can be seen on the side of the bus.
Murder Ain't What It Used to Be! - S1-E7
Revealing mistake: Jeannie is not supposed to see Marty at all, but when she is in her flat and she is getting up off her sofa, she is seen walking around him, as if she can see him.
Other mistake: The banner over the platform says "Miss Vestal Virgin 79 B.C.", when it was earlier announced several times as the 72 B.C. Vestal Virgin festival.
Continuity mistake: When Dum-Dum cuts the rope releasing Chug-a-Boom from the balloon, we cut to the car and you can see Clyde and Dum-Dum are surrounded by the rest of the Ant Hill Mob, but when we see the two in the next shot, the other members are nowhere to be seen.
Revealing mistake: In the song "Living Island", we see Judy frog jumping over Pufnstuf. When she goes back down, the wires holding her up and putting her down are visible.
Continuity mistake: When Nguyen falls of a building, breaking his leg he is taken to the hospital. Laying in a bed adjacent to him is another patient. The next shot is a close up of Nguyen. When the shot goes to a far shot Nguyen is alone in his room, the other patient and his bed is gone. (00:41:10 - 00:41:45)
Continuity mistake: When Floris and Sindala ride out the gate by surprise, the cook's position (he was opening and closing the castle gate to let them through) is different when the camera changes.