K is for Kill: The Tiger Awakes (1) - S2-E8
Visible crew/equipment: Steed is seen driving along with Purdey and Gambit in rural France. The camera was probably mounted on the front passenger side door, pointing in. As they near their destination, the camera pans to reveal a farm house, and as it pans, a professional-looking microphone can be seen sitting on the dashboard.
K is for Kill: The Tiger Awakes (1) - S2-E8
Visible crew/equipment: A Russian solder peers into a Salvation Army hall. In the shot that follows, from his point of view, there's a very obvious studio light on a tripod in shot.
The Last of the Cybernauts ...?? - S1-E3
Continuity mistake: At the start, Kane crashes an Austin Westminster - the burnt out wreck seen in his lair is a Wolseley 6/99.
The Tale of the Big Why - S1-E8
Visible crew/equipment: When Gambit is on the wing of Turner's plane, there is a close-up of Turner where a crewmember is visible in the background.
Revealing mistake: Our heroes arrive at an RAF base. Purdey hears a loud aircraft noise and looks up to the sky - cut to shot of a fighter jet. For a few frames after the cut, a caption that reads "The Engineer in the RAF" is just visible. It would seem they 'borrowed' some material from an RAF training film. (Indeed, a later shot of shells exploding was obviously taken from a videotaped TV programme, judging by the 'lag' effect caused by the tube camera that would've been used).
Continuity mistake: The yellow Aston Martin DBS that Gambit and Purdey give chase to at 0:09:45 transforms itself into a yellow Audi 100 Coupe at 00:15:00. Also the "P" registration mark (1975-6) on the Aston is incorrect as the marque had been discontinued in 1972.
Cat Amongst the Pigeons - S1-E5
Visible crew/equipment: When Purdey runs to Steed's front door after finding the 'Sanctuary of Wings' ring, the boom mike appears in the bottom left of frame as she calls after Steed.
The Last of the Cybernauts ...?? - S1-E3
Continuity mistake: During the car chase in the car-park, Kane's contact crashes into a purple Hillman which reappears undamaged later in the scene.
The Last of the Cybernauts ...?? - S1-E3
Audio problem: During the opening scene when the cast are gathered around the piano singing "Happy Birthday" to John Steed, his voice is audible as a part of the singing from the start, but he doesn't start singing until the second line.
The Last of the Cybernauts ...?? - S1-E3
Factual error: When Kane pushes the Range Rover into Gambit, the hand print in the Range Rover's boot looks more like it was made in clay, not the steel panel of a car (which would have simply dented).
K is for Kill: Tiger by the Tail (2) - S2-E9
Visible crew/equipment: When Purdey and Gambit are sitting on the balcony waiting for Steed, as Steed enters through the balcony doors, you can see the sound boom reflected in the door window behind him. (00:23:20)
Continuity mistake: When Purdey is talking to Steed through the window of his hotel room, her hand positions change between the exterior and interior shots. (00:33:40)
The Tale of the Big Why - S1-E8
Revealing mistake: When Gambit is just about to shoot off Steed's door handle, the 'marble' column behind him wobbles visibly.
Continuity mistake: During the snooker game between Steed and Gambit, Steed plays right-handed but in the close-ups of the trick shots, the cue is held left-handed.
Cat Amongst the Pigeons - S1-E5
Continuity mistake: When Purdey and Gambit are escorting Rydercroft from his plane, the registration number is ATUC. Later, when he gets back into the plane to take off, the registration number is G-ATPN.
Dead Men are Dangerous - S2-E1
Visible crew/equipment: When Steed comes out of his house following the sound of the loudspeaker, two studio lights can be seen reflected in the windows.
Medium Rare - S2-E3
Visible crew/equipment: When Wallace meets Purdey and Steed as they examine Freddy's body, the boom mike dips into shot.