Visible crew/equipment: When the fake ambulance that the crew made to infiltrate St. Mary's hospital lands at the main entrance, it lands on flat foot pads. But in the following shots the casters that were used to move the prop around the set are visible beneath the landing feet.
Continuity mistake: As Mal approaches the desk, saying "we got a couple of DOAs" he puts his left hand directly on the corner. Cut to a shot from behind and his hand's moved about a foot.
War Stories - S1-E9
Revealing mistake: During the firefight on Niska's ship, when Simon sees a guard coming and says to Sheppherd Book, "Book, we, uh-", a dead guard on the floor moves his legs as the guard that Simon saw fires his weapon. (00:37:10)
War Stories - S1-E9
Continuity mistake: As Zoë is walking through the halls of Niska's ship to give him the money, her hands keep switching from raised to down by her sides.
War Stories - S1-E9
Continuity mistake: During the torture scene, Wash has quite a large stomach. But after he is saved by Zoë, his stomach is considerably smaller.
War Stories - S1-E9
Continuity mistake: In Niska's office, behind his desk, there is a door that slides open to a small torture chamber. In "War Stories," there is a small staircase that leads into this torture chamber behind the door. However, in "The Train Job" (the first time we see this chamber) there is no staircase.
War Stories - S1-E9
Continuity mistake: In the scene where Malcolm Reynolds is being tortured, after Zoë takes Wash away, the villain cuts off Malcolm's left ear. The shot changes, and then returns to Malcolm, showing the other side of his face. Now the visible ear, the right one, is missing. The shot changes to the front, and now his left ear is missing again.
War Stories - S1-E9
Continuity mistake: The size of the red marks on Wash's body change from when he first leaves the torture chamber to going into the cockpit of the shuttle.
Continuity mistake: When Early drops an unconscious Mal down the hatch to his room, in the shot from above Mal falls with his arms by his side, but in the next shot when he lands, his arms are above his head and fall to his sides when he hits the ground.
Visible crew/equipment: As the camera goes down through the ship to River standing on the catwalks in the cargo bay (eavesdropping on the crew as Kaylee tells them about how she killed the 3 guards on Niska's ship in War Stories), look at the kitchen table on the far right of the screen. There is a man with white hair bent over the table reading a book. He isn't part of the ship's crew, more likely part of the film crew.
Continuity mistake: In the close-up shot of the explosive in the sticky substance being applied to the outside of the cargo hold, the pink wire sticks out at the bottom, and in a loop in the middle. In the next shot, from slightly further back, the wire doesn't stick out anywhere, and the shape of the explosive ring has changed and become more oval. (00:05:30)
Revealing mistake: In a travelling shot, you can see an extra in the middle of the street, looking at the camera and waiting for his cue to start walking. (00:17:26)
Visible crew/equipment: As Wash leave the ship to get supplies, you can see a hand pulling the front of the quad. (00:17:58)
Revealing mistake: Toward the beginning of the episode, when we first see Inara at the controls of her shuttle, she is holding the steering wheel upside down as she flies away.
Visible crew/equipment: As Serenity touches down on the Eavesdown Docks on Persephone, a crew member can be seen pushing Wash's mule down the ramp just after Mal talks to Kaylee about passengers and the ship's Compression Coil.
Visible crew/equipment: When Wash tells Zoë to be careful as they touch down on the Eavesdown Docks on Persephone, a hand can been seen pulling the Mule down Serenity's ramp in the bottom right corner of the shot as Wash leaves.
Visible crew/equipment: When Simon asks Mal why he is so scared of the Alliance, Mal punches him. On the bottom left side of the screen, someone's hands are visible catching Simon as he falls.
Continuity mistake: At the beginning of the episode when Mal, Jayne and Zoë are ransacking the destroyed ship for supplies, after Mal says "Vault's sealed" there is a shot of Mal as he inspects the door hatch before asking Jayne for the explosive gel gun. The ring around the door hatch's handle from the explosive gel gun is already visible in this shot.
Chosen answer: One of the premises of the show is that the two major Earth societies that survived, and ultimately merged, were the Chinese and Americans. As a result the common language includes much Chinese. Clothing, signage, and building designs also have a heavy Chinese influence.