Requiem for Methuselah - S3-E19
Continuity mistake: When looking at the view screen from the helm, there is a man sitting at the Conn position, but in the wide angle, there's a woman there.
Requiem for Methuselah - S3-E19
Other mistake: If the ship had not been in visual communication, there's no way Kirk could have seen the Bridge or the crew in suspension.
Continuity mistake: In the 40th Anniversary release of the complete original series, this episode opens with Scotty at the conn, making an extended log entry, wearing his third-season swept-back hairstyle, and it is very obvious that he is visually mouthing several completely different sentences than we hear in the audio. After the opening credits roll, we next see Scotty wearing his more typical relaxed hairstyle with slight bangs. It is apparent that, in remastering and editing this episode, they inserted footage of Scotty from another episode altogether. For whatever reason, it is a glaring mistake of both continuity and audio editing.
Continuity mistake: Just before Parmen starts mind-controlling Kirk, McCoy and Spock, he presents them with three gifts. Kirk receives a large, gold Greek shield, which the captain holds with both hands, in front of him, as the lengthy scene continues. In the wide shot, Kirk is holding the shield high up on his chest, completely obscuring his Federation insignia. In subsequent close-ups, Kirk is holding the shield down low, around waist-level, fully exposing his chest and insignia. Every time the camera cuts back to wide-shot, Kirk is again holding the shield up high on his chest.
And the Children Shall Lead - S3-E4
Continuity mistake: When Gorgon the Angel is on the bridge with the children, the positions of the children are different depending if the shot is from the rear of the children or the front.
Revealing mistake: As the camera is close to Dr. Sevrin, the line of the bald skin wig is easily seen.
Let That Be Your Last Battlefield - S3-E15
Revealing mistake: As Kirk turns all the way around to look at the newly arrived Bele, the shadows of the stage wiring is easily spotted at the top of the screen.
The Enterprise Incident - S3-E2
Continuity mistake: When the guard opens the cell barrier, the light bars turn off, then slide back. As they come back out, they're already on, rather than the reverse of the opening procedure.
The Enterprise Incident - S3-E2
Other mistake: As the Romulan commander goes to answer the intercom, the switch she touches to open the link is already on, probably left that way from a previous take.
Other mistake: As Kirk nears the portal, the edge shimmers just before he gets to it. As he goes through it, his actions are greatly slowed rather than natural.
Continuity mistake: After Kirk knocks the jailer out, there's a bit of stew on the cell's door above the lock. After Kirk drags the man into the cell and closes the door, the bar above the lock is clean and dry.
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.
Let That Be Your Last Battlefield - S3-E15
Other mistake: When preparing to go around again, Sulu and Checkov start working their controls. When there is a close up of Sulu's hand, it's obviously a re-used shot of Kirk's hand starting the 30 second count down timer on the Constellation in "The Doomsday Machine" (S2 E6).
Let That Be Your Last Battlefield - S3-E15
Revealing mistake: After Kirk shuts down the self destruct, he asks Spock if the ship is heading for Arianas. At one point in the dialog, you can see the display for the self destruct sequence is still on the screen, just not lit up.
Let That Be Your Last Battlefield - S3-E15
Revealing mistake: When the camera is close up on Beal's face, you can see a bit of real flesh color where the black and the white greasepaint used didn't quite match up.
Continuity mistake: When Kirk intervenes to keep Losira from touching Sulu, she jumps back about two feet and stops. When the camera cuts to look at her, she's still moving, and is about ten feet from Kirk.
Other mistake: After Kirk makes the cairn of rocks to bury D'Amato, he places a rock with the man's name on it. If the phasers couldn't cut the rocks of the planet, how did he cut a squared rectangular rock, and how did he put D'Amato's name on it?
Audio problem: When Chekov goes berserk on the bridge, he emits a scream and shoves Spock. When Spock holds Chekov's face, the closeup on Chekov shows a scared look, and the original scream is played again, but Checkov's mouth doesn't match.
Other mistake: After the shot of McCoy checking Sickbay, there's a shot of Chekov. It was a quick shot but it can be seen that the film was run back and forth through about a second, as his movements can be seen to repeat rapidly in reverse and forward twice. (00:06:56)
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.