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)
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."
Answer: Kirk was getting his physical and Dr. McCoy probably turned off communications, because if he hadn't, Kirk would have left and headed straight for the bridge, leaving McCoy irritated.