Continuity mistake: On the first map we see of the Romulan Star Empire, the two planets are Romulus and Remus. But the map later reads "Romulus" and "Rom II."
Continuity mistake: Midway through the episode, a stock shot of the view screen shows Sulu at the helm. When we return to the bridge master shot, however, Sulu isn't there. Styles is the only one at the console, and he's sitting at navigation. The helmsman's chair is empty. (00:32:05)
Continuity mistake: When Spock races back into the phaser control room, he places his electronic tablet on the console and kneels to check on the unconscious Styles and Tomlinson. From one shot to the next, the tablet changes its position on the console behind him. (00:40:00)
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