Other mistake: The red alert light at the entrance to the chapel blinks a few times and stops, even though the rest are still flashing. Also, the last thing Kirk says is "All decks, condition red", which is unnecessary, since the red alert has already begun sounding.
The Man Trap - S1-E2
Audio problem: As Kirk low crawls behind some boulder and grass, his communicator flips open and closed. If it was opened, the sound of the channel opening should have been heard, but wasn't. (00:36:35)
Continuity mistake: In the first scene when Spock is piloting the shuttle craft out of the Enterprise and into space, as the bay doors open you can see both the ship's shuttles, the Galileo, and right behind it the Columbus. Yet as soon as the Galileo clears the bay doors, in the immediate reverse shot, the bay is empty and the Columbus has disappeared. (00:01:45)
The Ultimate Computer - S2-E24
Continuity mistake: When Sulu is first reporting the M-5 movements, Kirk's hand alternates between being up at his temple and down by his mouth, too quickly to be real.
Revealing mistake: In the close up shots of the mirror Sulu, the poor make up job of the scar on his face is very evident.
Continuity mistake: When Kirk and Spock get to Sick Bay, the doors open to reveal Nomad coming out. But the shot of Nomad coming out is a re-used shot of it coming out of the Turbo Lift, not the Sick Bay, as the nameplate said. (00:42:10)
Space Seed - S1-E23
Continuity mistake: At the compression chamber, the pressure meter goes from thirty to ten too quickly to be accurate between shots. After showing ten, the meter jumps back to twenty.
Revealing mistake: As Kirk fights Finney in the Engine room, in the long shots, Kirk's stunt double is easy to pick out from the close shots.
Tomorrow is Yesterday - S1-E20
Revealing mistake: As the camera looks at the pilot in the cockpit, there are supports on either side of and behind him as well as no clouds where there should be, showing he is on a sound stage set.
Continuity mistake: After DeSalle tries, and fails, to call the ship, he shakes his communicator, and the grille closes, but is opened again in the wide shot.
Continuity mistake: As the Galileo re-enters the atmosphere, you can see Scotty in the copilot chair. His hair is parted on the left side, but in the interior shot, it's parted on the right.
Continuity mistake: After the wild man is down on the mound, his right hand is under his body. In the close up, it's on the frame of the trike. (00:05:05)
What Are Little Girls Made Of? - S1-E8
Continuity mistake: As Kirk talks to Ruk, a closeup of Kirk shows a few strands of hair down over his left eye. In the regular shot, it's normal.
What Are Little Girls Made Of? - S1-E8
Continuity mistake: As Ruk is being questioned, he's standing in the open door. As Kirk grabs his arm to keep him from leaving, Ruk is suddenly half way in the room without moving.
What Are Little Girls Made Of? - S1-E8
Revealing mistake: As the big android holds Kirk up by the wall, you can see the skin wig worn by the actor wrinkle up.
Requiem for Methuselah - S3-E19
Revealing mistake: As Kirk pulls the shroud away from the Rayna duplicate, look closely at the part of her head just below her left ear. The bald cap she wore to conceal her hair and give her an unfinished look.
Continuity mistake: When Checkov turns on the viewer in the transporter room, the Defiant is seen directly from the starboard side, when it should have been seen from the quarter profile port side, as it was drifting to the Enterprise's port side.
Other mistake: When the transporter comes on to beam up Pike, the blonde ensign goes to face the transporter. As she does, she glances down at the floor to find her mark, and stands on it, looking into the chamber.
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.