Continuity mistake: After Micky has just taken apart the Klutzmobile engine and the Baron has run over to the periscope, in the next scene, Micky has magically been re-tied in a chair, even though neither Wolfgang nor the Baron tied him up again.
Visible crew/equipment: After Micky and Crumpets have been kidnapped, the amount and the slackness of the rope around Micky changes between the close-up and wide shots.
Answer: The Monkees TV series was very much a fantasy (this was the "groovy" psychedelic 60s, after all). Impossible things, such as items appearing out of nowhere, happened on their show without explanation all the time.
Jean G