The Talons of Weng-Chiang - S14-E6
Factual error: The Doctor mentions at one point in the story that he had once been fishing in the River Fleet with the Venerable Bede. The Venerable Bede was a distinguished 7th century scholar, who lived his entire life at Jarrow, on Tyneside, and never at any time came to London.
Factual error: It is stated that removing all the plants caused carbon dioxide levels to drop. But plants absorb carbon dioxide, so removing them would create an increase.
Underworld - S15-E5
Factual error: While it's true the centre of a planet would have no net gravity, the weightless condition would be everywhere, not concentrated in a convenient shaft.
Factual error: The Doctor meets Jamie at a time after the Battle of Culloden. But here Jamie says he met him in 1745. Culloden took place in 1746.
Factual error: When the inside of an apple is exposed to the air for about fifteen minutes it oxidises and goes brown, but Jo's breakfast apple goes brown by the end of the scene. (This is assuming she wasn't deliberately eating a brown apple).
Factual error: In Episode 3, Zarof fires a gun. The muzzle is seen and a sound is heard but the gun doesn't move and there's no smoke or bullet, no flash or anything at all. (00:23:05)
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