Visible crew/equipment: Part 4, A Race Against Death: The Doctor chides the First Elder about Ian's illness and says, "I must have chemicals and equipment; his death will be your fault and yours alone." Then, just as the Second Elder appears and says, "Sir," the boom mic (with white end) swings up between the two Sensorites, and we also see the diagonal boom pole moving at the left side of the screen.
Other mistake: In episode one, when the crew wonders what The Sensorites will do to them, the camera zooms in on the Doctor as he says, "or kill us?" It then jerks with an audible click as though hitting something.
Continuity mistake: Part 6, A Desperate Venture: The new Second Elder threatens Carol and has her write a note to John. When Carol hands the finished note to the new Second Elder, this close-up dissolves into another close-up of the note being held by Barbara. Carol's note is quite different in both of these close-ups.
Visible crew/equipment: Part 5, Kidnap: In the Sensorite lab, the Scientist shows the Doctor and Ian a collection of things left behind by the humans, who were killed in the spaceship explosion. When Ian flips through the family snapshots, the shadow of the boom mic passes over Ian's forehead. It happens again just as Susan blurts, "The City Administrator, of course!"
Visible crew/equipment: Part 4, A Race Against Death: While Susan is with Ian and the First Elder, Ian tells her, "The Doctor must have run into a snag..." When Susan replies that she's going to find out why, just as she stands up a boom mic becomes visible at the top right side of the screen, and it's pulled up out of view. Then, as the First Elder says, "I will have you conducted to the laboratory," the shadow of the boom mic is on his head.
Visible crew/equipment: Part 4, A Race Against Death: After the Doctor states he's going off on an expedition, John still struggles to warn the Doctor, and when the Doctor tells Carol, "Now you stay with him, I think he's getting better," a boom mic becomes visible at the top left side of the screen.
Visible crew/equipment: Part 3, Hidden Danger: When the First Elder tells the Doctor, Ian, and Susan about their refined aqueduct water beneath the city, Ian drinks some of it. Then just after the Doctor says, "Vintage water," the tip of the boom mic sweeps across the top of the screen.
Character mistake: A Sensorite says, "Give my Doctor the congratulations," instead of "Give the Doctor my congratulations," in the fourth episode.
Continuity mistake: Drill marks are visible on the door before Maitland uses the drill on it.
Answer: In 'The Five Doctors', three separate Cyberleaders are definitely used. So it's likely that Cyberleaders are like unit commanders, of which a fair-sized army might have several.
Daria Sigma