Continuity mistake: McCoy uses a "masking device" to block out the bridge personnel's heartbeats. When McCoy masks Spock's heartbeat, he holds the microphone, err, masking device over the wrong part of Spock's anatomy. We'd already established that Spock's heart wasn't in the same place as a human.
Continuity mistake: They said that engineering was "B" deck which is deck 2, but engineering is deck 7 which would be "G" deck.
Continuity mistake: In the finale of the fight between Kirk and Finney, Kirk's shirt is torn, exposing his right shoulder and arm. As Kirk (the stunt double) goes for the knock out blow, the shirt is only a little torn in the front. Then the close up on Kirk catching Finney, his shoulder is exposed again.
Continuity mistake: During Kirk and Lt. Shaw's conversation where Kirk learns that Shaw will be the prosecuting attorney, they are sitting at a table. A shot from behind Shaw's left shoulder shows her turning her head toward Kirk. The scene then shifts to a close-up front shot of Shaw, where she again turns her head.
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