Continuity mistake: As Kirk speaks with Commisioner Ferris, Kirk's hands go from holding a piece of equipment to being straight down by his side, back to holding the equipment.
This Side of Paradise - S1-E25
Continuity mistake: When Kirk and Spock successfully activate a subsonic transmitter, it cuts to a closeup of a spade's metal blade breaking the soil ground, but in the next wide shot Sulu and DeSalle are using two spades made entirely of wood. (00:44:45)
Continuity mistake: In the beginning Chekov disappears off the bridge for a moment and is replaced by a blond haired crew member, then he returns.
Continuity mistake: While Flavius guides Kirk, Spock, and McCoy to the city to find Merik, the foursome stop behind a group of trees. In the first wide shot, as Flavius explains they'll wait until dark, there are no red marks on the tree trunks, but in their closeups there are a few red marks (presumably from squibs), before the gunfire has even occurred. At the start of the second wide shot the tree trunks are still void of those marks, and when the police shoot at them that's when the red marks appear. (00:15:15)
Continuity mistake: When McCoy places the old tricycle down on the ground, the handlebars are facing the right with its wheels facing the left. When McCoy is attacked by the diseased Only, Kirk and Spock subdue him, and as he lies on the ground the tricycle flips over between shots, so the handlebars suddenly end up facing the left. (00:04:30)
The Immunity Syndrome - S2-E18
Continuity mistake: When McCoy escorts Spock to the shuttlecraft hangar McCoy is wearing his short-sleeved medical tunic, but when Spock suggests that the doctor could wish him luck, in the next closeup McCoy is wearing his long-sleeved uniform. (00:29:40)
Continuity mistake: When Kirk's arrow hits Kras it protrudes from his leg, but in the next wideshot as Kras screams and stumbles the arrow is quite gone from his leg, but three shots later the arrow is back in his leg while he tries to pull it out. (00:43:40)
Continuity mistake: After McCoy checks the Horta, he approaches Kirk with his tricorder in his left hand. The scene cuts to McCoy and Kirk and now McCoy's tricorder is in his right hand.
Continuity mistake: Spock and Kirk both arrive at the sizzling remains of a red shirt crewman, standing close together, but the next shot of the crewman's remains shows only one set of legs at the site (presumably Spock's), not two.
Continuity mistake: As Gary Seven beams in, Scotty's hair changes between shots.
Continuity mistake: As Mira is speaking with the alien's voice, Spock is behind a console that has a piece of equipment attached to it. From behind Spock, the piece is to his left, but the close ups of Spock show him close to and directly in front of it.
Continuity mistake: When Mr Hengist goes on the rampage in the hearing room, Kirk pushes Yeoman Tankris behind him. However, when we see Kirk punching Mr Hengist in the jaw in the next shot, Tankris is missing, and in the shot after that, she is back again.
Continuity mistake: When Nomad first appears on the bridge, the indicator light on Scott's communicator panel is on. A second later, it's off, and he turns it on to say his line.
Continuity mistake: On the bridge, watch Uhura. She goes from both hands on her controls, to left hand on her earpiece in a split second.
Continuity mistake: After Spock tells Boma and Gaetano that he's in command and they should fire only to frighten, not to kill, one of the creatures throws a spear and then his shield at the trio, and when the shield hits the ground it's much smaller than the huge shield lying on the ground in the next close-up. (00:23:15)
The Conscience of the King - S1-E14
Continuity mistake: After the phaser explodes in the pressure vent disposal unit, just before Kirk walks into Karidian's quarters there's a crown and board on the table beside Karidian, but when Kirk gives the paper to Karidian for him to read, the board is suddenly on the opposite side of the table, though it has not been touched.
Continuity mistake: As Decker is talking about the Planet Killer, the camera looks at McCoy. His left eyebrow is slightly arched, and his hair is styled differently. It can be seen that this shot is reversed from normal.
Continuity mistake: As Kirk is crawling through the tunnel leading to the Horta's nest, a tight view from his left side shows light shining on his face and darkness behind him. When the shot changes, though, to the view from the nest, there is light behind him and darkness on his face.
Continuity mistake: After Spock talks about Sun Worship on the bridge, Uhura goes to correct him. As she's sitting at her console, her arm is covering the note board. When the angle changes to include her, Kirk, Spock and McCoy, her arm is above the note board. Back to a close up, and her arm's covering it again.
Continuity mistake: When Kirk, Bones and Spock are commanded to stop, and raise their hands, they do so. After a moment, Kirk starts to lower his hands. After the camera cuts to a shot from behind, Kirk's hands are by his sides and he goes for his phaser. After another warning shot, he says "I think he means it." The camera goes back to facing them, and his hands are up again.
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.