Is There in Truth No Beauty? - S3-E5
Deliberate mistake: While Miranda is with Kollos, McCoy tells Kirk that he didn't reveal her secret because he respects her privacy, then when Miranda steps out of the room and concedes to obey, the next closeup of Kirk is a flipped shot. (00:34:05)
Deliberate mistake: So that he can look in the right direction, toward Lincoln, a shot of Kirk is reversed before the first battle, putting his uniform insignia on the wrong side. (00:25:45)
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