Continuity mistake: When Miramanee and her companion first see Kirk at the obelisk, the two women are standing, holding their fruit baskets, just inches from each other. In the very next, reverse angle shot, they're suddenly several feet apart. (00:09:10)
Continuity mistake: When Spock orders the phasers to fire, they shoot outward from the ship at an angle from each other, but when they hit the asteroid they converge at a single point. (00:24:00)
Continuity mistake: When the Enterprise is trying to push away the asteroid using the deflector, a quick shot of Uhura is shown from stock footage of "And the Children Shall Lead," but she is not in the rest of the episode.
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.