Owen and Tosh compare the corpse's wound to John Hurts death scene in Alien, John Hurt would later become the War Doctor a previously Unknown incarnation of the Doctor in the 50th anniversary special , making this the only time in the entire series be it the original Doctor who or any of it's spin offs that an actor has been alluded to who later appeared in the series as a character.
Although this is the seventh episode, it was the third to be filmed.
This episode takes place in 1812 and 2007.
Daniela Denby-Ashe and John Barrowman have both appeared in the sitcom My Family, where Daniela played the daughter (and as a result, one of the protagonists) Janey and John was guest in the episode The Guru (2009),
When Tosh stops the man from killing his family, she clocks him over the head with a golf club. When it came time to shoot the scene, Naoko Mori accidentally REALLY hit the man, hard, instead of stopping just short of making contact.