Stupidity: Apparently Doug, Tony, and the Time Tunnel technicians have no qualms about changing/interfering with the timeline of history by either badly injuring or killing people whose descendants could have affected and altered the future of the Time Tunnel crew and history itself.
The Revenge of Robin Hood - S1-E16
Stupidity: The guard outside the dungeon door hears the sword fight between Tony and the two guards inside, and tries to open it, running away to get help and returning with men and a battering ram. Why did he not have a key to open the door in case something went sideways, i.e., a sword fight in the dungeon?
The Revenge of Robin Hood - S1-E16
Stupidity: The Time Tunnel technicians send a homing beacon to the dungeon to help Tony and Doug, but through the episode nobody notices the well-lit, futuristic-looking object propped against the dungeon wall next to the door.
Stupidity: Aside from Nimon starting the gun battle, Sgt. Jiggs and his men have no concern letting bullets fly about in a room full of expensive and important equipment used for the Time Tunnel project.