Other mistake: Usually Master Sergeant Jiggs and his men are posted as guards in the Time Tunnel control room at all times, but when Merlin shows up in the control room a second time, there are no guards to be seen.
Time Tunnel (1966)
1 other mistake in Merlin the Magician - chronological order
Starring: James Darren, John Zaremba, Robert Colbert, Whit Bissell
Rendezvous with Yesterday - S1-E1
Character mistake: When Tony talks to captain of Titanic he states he was born in 1938, but in episode 4 "The Day the Sky Fell In" it is December 1941, he should be 3 years old, but as a young child he is about 12 years old.
Trivia: The same prop used as the Time Tunnel homing beacon in "The Revenge of Robin Hood" and part of an alien ship in "Visitors From Beyond the Stars" makes an appearance in this episode.