Continuity mistake: When the old man dies and Owen is trying to revive him, the position of the man's head changes several times between takes, from lying flat to propped up on the pillow and back again. (00:37:00)
Plot hole: Owen is unable to give Henry the kiss of life as he has no breath, and yet he is able to talk.
Factual error: Jack calls Gwen, and when Rhys takes the phone and hangs up on him, Jack's cell phone, for the second time in the series, sounds an audible, impossible dial tone. (00:13:00)
Exit Wounds - S2-E13
Continuity mistake: In 1-8 They Keep Killing Suzie, Gwen has a Saab 900 5 door. However, in this episode Reece is driving a Saab 900 3 door that everyone has to squeeze into. Same registration number, but different vehicle.
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)
Children of Earth: Day One - S3-E1
Character mistake: Lois says that Colonel Aduya's uniform "isn't British Army". In fact, it is entirely (and accurately) British Army with the exception of the small UNIT badge over the pocket.
Children of Earth: Day One - S3-E1
Factual error: On the government database, Torchwood is described as being founded by HRH Queen Victoria. As a sovereign, she was actually HM (Her Majesty) not HRH (Her Royal Highness).
Children of Earth: Day Two - S3-E2
Continuity mistake: When Gwen and Rhys are travelling to London in the lorry full of potatoes, Rhys picks up a potato in his right hand. However when the shot changes, he is holding it in his left hand. (00:29:40)
Children of Earth: Day Two - S3-E2
Character mistake: When lanto is in the park and the children all stop the camera shifts to look at a little girl in pink. But in the top left corner there is a young blonde girl still moving and looks to be silently mouthing a word as she steps off the roundabout. (00:32:08)
Children of Earth: Day Two - S3-E2
Revealing mistake: When Ianto drops the concrete cell into the quarry and it breaks apart, the green foam from which it is made becomes visible. It is evident that the outside of the block was painted to resemble bricks and concrete block. When this breaks apart on the ground, the inside becomes visible, showing the concrete and brick textures are only surface deep. (00:53:05)
Children of Earth: Day Three - S3-E3
Factual error: Frobisher tells the 456 he is the Permanent Secretary of the Home Office of the "United Kingdom and Northern Ireland". It should be the United Kingdom of Great Britain and Northern Ireland. Northern Ireland is part of the UK.
Children of Earth: Day Three - S3-E3
Factual error: Andrew Staines was a junior Scots Guards officer in the 1960s according to the Torchwood database. However, the photograph of him in that era shows him with a general's capbadge.
Miracle Day: The New World - S4-E1
Factual error: When Rex is crossing the newer Severn Bridge (when still on the bridge) he sees paying kiosks. The kiosks for this bridge are in Wales, significantly after you have come off the bridge, and would not be in plain sight when you cross.
Miracle Day: The Blood Line - S4-E10
Continuity mistake: At the very end of the episode, when Rex is checking his phone, when the camera is facing him, his phone is being held in portrait, but when the camera is over his shoulder, looking at the screen, the phone is in landscape. This is shown twice, when the camera shots switch. (00:53:35)
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