Revealing mistake: From the first "front on" view of Gwen and Owen in the arcade as they are running to catch the alien device, you can see behind Gwen to the right that Owen is being played by a stunt double.
Torchwood (2006)
1 revealing mistake in season 1
Starring: John Barrowman, Eve Myles, Gareth David-Lloyd, Kai Owen
Children of Earth: Day One - S3-E1
Revealing mistake: When the children are possessed by the 456, they're supposed to be frozen and stare blankly ahead. But during the second possession, as the camera is panning across a school playground, a boy on the far right is looking directly at it. As it moves closer to him, he swivels his eyes back to where they're supposed to be. (00:16:30)
Captain Jack Harkness: Under normal circumstances, an exuberant Roman soldier would be my idea of a perfect morning.
Trivia: Eve Myles, who plays Gwen also plays the maid character Gwyneth in the Doctor Who (season one) episode "The Unquiet Dead."
Question: How did Jack get the Doctor's severed hand?
Answer: He might have requisitioned or stolen it from Torchwood London, or he might have been ready down below once it'd been severed, searching for "the right Doctor" and not knowing that the newly-regenerated Doctor was the one he was looking for.
Captain Defenestrator