10 Times The Doctor Wasn't Very 'Doctory'
3. The Runaway Bride - Drowning The Racnoss Children
The Racnoss were an ancient race from the Dark Times of the universe, where they were one of many enemies of the Time Lords. The survivors of their war fled in a ship which the Earth formed around. In 2007, the Empress of the Racnoss discovers these survivors and starts a plot to awake her young.
However, as usually in Doctor Who, she is beaten by the Doctor. But in an unusually dark turn of events, when the Empress doesn’t take the Doctor’s ultimatum, he does something kind of unexpected. The Doctor floods the tunnel down to the centre of the Earth with water from the Thames and drowns all the Racnoss young…
Whilst the Empress escapes, however not for long, we’re led to believe this is the last of the Racnoss. The Empress flees to her ship, not long before being destroyed under orders from Harold Saxon.
Therefore, it isn't hard to argue that the Doctor has a serious hand in committing genocide, by wiping out the species young. Not something we’d usually see or expect from the Doctor, especially when the Racnoss young were effectively helpless.