This is the only episode not to feature any female characters, and one of only two episodes not to feature Tin-Tin (the other being "Lord Parker's 'Oliday").
First episode to feature an on-screen title.
The first episode to feature The Mole in the closing credits.
The futuristic remote camera would be one science fact with the introduction of modern drone technology, though early drones had already been in service for some time.
The small white microphone used by the senior officer in 'Copter Watchdog' and seen again in many other episodes is a DIN plug - an audio connector measuring approximately 16mm in diameter and 70mm in length. Normally available in black or grey, it is extensively used from the 1960s onwards for connecting low level audio signals to and from amplifiers in home hi fi systems.