10 Doctor Who “Mistakes” That Were Totally Intentional

Time Agent turned Torchwood supremo Captain Jack Harkness is first introduced in the Series 1 two-parter The Empty Child/The Doctor Dances.

Here, we learn all sorts about this loveable rogue: that he's from the future, that he's attracted to anything with a pulse, and that he can travel through time using his wrist-mounted vortex manipulator.

In one scene towards the end of The Empty Child, Jack uses his "space hopper" to scan one of the gas mask-wearing zombies. The device is clearly on his right wrist here, but just a few seconds later, it's moved to his left.

As confirmed on the episode's commentary track, this was because the shot was intentionally flipped during editing.

Something was clearly off and the filmmakers wanted to make the shot work better, necessitating the post-production shift. Ultimately, it's a very minor detail, but exactly the sort that you can't unsee once you know it's there.