Continuity mistake: In the opening scene, Gwen has a long, loose strand of hair hanging over her left temple - but every time the camera angle changes, it disappears. (00:01:00)
Continuity mistake: When she sees the little boy's ghost, Gwen's hair alternates repeatedly between neatly-combed and windblown/messy, depending on the shot. (00:03:30)
Countrycide - S1-E6
Continuity mistake: In the pre credits sequence, when the lady gets out of her car the antagonist slashes her rear tyre however after the antagonist is attacking her inside the car we see a rear shot of the vehicle, and the tyre is fully inflated.
Continuity mistake: While she's talking to Mary in the flat, Toshiko's hair keeps changing between shots, going from combed evenly to split apart with one section hanging in the middle of her forehead and the rest brushed back. (00:31:30)
Out Of Time - S1-E10
Continuity mistake: John is about to eat liver and potato with Emma before she storms out saying, "I don't like liver". While they are talking, the potato is facing Emma and Gwen. After Emma leaves, the liver faces Gwen and the spot where Emma was.
Continuity mistake: During the interrogation sequence in the Torchwood hub Gwen's position moves in relation to the grate from the centre to the sides between shots.
Continuity mistake: In the scene on the pier with Toshiko and Tommy, the soldier from WWI, Toshiko is holding her hand bag but drops it when he picks her up. Immediately, the next shot she is holding it again.
Continuity mistake: Gwen views a transparency of two Torchwood members from 1918. The words "Torchwood" can be seen behind them. When Ianto takes the transparency and holds it up, the slide is different: it contains five people and the word "Torchwood" is above their heads.
Continuity mistake: While he's in the van with Jack, Rhys's seat belt shoulder strap vanishes and reappears multiple times as the shots change. (00:27:40)
Continuity mistake: When the man is being terrorised by the weevil, in close up shots, the weevil is about 6 inches from the man's face. However in the long shots, it is about 3ft away from him. (00:34:35)
Continuity mistake: When Maggie walks away from the car accident, the blood smears on her white gown change repeatedly from shot to shot. (00:16:30)
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)
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 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)
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: Several times during the episode, most notably at the beginning when the old grave is discovered, Tosh holds a devise that looks a great deal like the Sonic Screwdriver that she uses to determine the age of the skeleton. However, a search of Google images shows that it is not the same thing.
OneHappyHusky