Continuity mistake: Initially, the Enterprise orbits Psi 2000 as the planet turns westward. But in later shots, on the bridge view screen, the planet has reversed directions and now turns eastward. (00:04:05 - 00:12:00)
Continuity mistake: As Scotty starts prying the panel open, it's with a tool in his right hand, and the thumb of his left. After the cut, he's suddenly holding it in his right hand.
Continuity mistake: As Christine goes to put the respirator in place, she uses her right hand. After the cut, it's her left that puts it in place.
Continuity mistake: As Bones works on Joe's injury, a red light turns on over his head shining down on the area, illuminating his hair. A second later, the red is gone, then back.
Continuity mistake: The indicators radically change positions when Spock gets on the bio bed.
Continuity mistake: When Sulu confronts the men in the corridor, his epee goes from perfectly straight to having a slight crook, then back to straight when he appears on the bridge.
Continuity mistake: As Joe draws back and stands up, he pulls a knife. First, it's sharp side up, then it's suddenly blade down.
Continuity mistake: In the opening, the crewman gets a few drops of the infectant on his hand, but the reddish mass on the wall remains. On the ship, when the spectral view is shown, the red mass is nowhere to be seen.
Continuity mistake: When Sulu first emerges on the Bridge, Kirk confronts him, and standing a couple feet from the rapier. A second later, Kirk's a few inches from it.
Chosen answer: If they're in orbit, they're being pulled along by the planet's gravity well, therefore, impulse engines would only be used for minor corrections and would be "on standby" while in orbit, but not active. (Like keeping your car idling without revving the engine and creating plumes of exhaust).
Captain Defenestrator
Thank you for the info.
Movie Nut