Continuity mistake: When Shepherd Book tells everyone about the electrical nets, Jayne says, "One day you're gonna tell us all how a preacher knows so damn much about crime." Shepherd then turns to leave. But in the immediate close up of him and Mal, he turns to leave again.
Continuity mistake: When Mal and Nandi are talking and drinking on the couch, the position of Mal's left arm keeps changing between shots. In both the closeup shots of Mal and Nandi, his arm is resting next to her on the couch, but in the shot of them both, his arm is behind her.
Visible crew/equipment: Tracey threatens the crew with a gun on the bridge when he hears that they're about to call the cops. He says that he'll blow a hole right through Wash if they do. There is a shot of Mal saying "You mailed your ugly business to Zoë and me, Tracey." As he says this, a crew member's hand can be seen above them (through Serenity's windshield on the left of the screen) grabbing one of the pieces of fallen ice.
Continuity mistake: In the scene where Jayne is telling Simon and River to keep clear of Saffron, he is holding some things wrapped in tin foil (possibly food). He places them on a table next to him. River then calls Saffron a liar. In the following shot of Jayne, one of the food packets has been torn open. River later says that "Jayne" is a girl's name. The food packet that was torn open is now intact.
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.