A Piece of the Action - S2-E17
Continuity mistake: When Kirk is talking to Oxmyx across the pool table, the yellow 1 ball is shown close to Kirk, then Oxmyx, and back.
Continuity mistake: During the hand-to-hand fight scene, the stunt double playing Spock gets his hair mussed up, but immediately after the fight, Spock's hair is neatly combed and formed, as it was before the fight.
Continuity mistake: The blood dripping from Isak's mouth changes sides.
Space Seed - S1-E23
Continuity mistake: As the away team observes Khan in the stasis chamber, McCoy holds his tricorder with both hands, but the next shot shows him holding it in one hand.
Space Seed - S1-E23
Continuity mistake: On the Botany Bay, McCoy is not holding his tricorder, but when the ship's lights activate, McCoy suddenly has his tricorder in his hands.
Space Seed - S1-E23
Continuity mistake: When Khan asks Kirk "How long?" Kirk's head is near Khan's with nobody behind his head, but the next long shot shows Scotty behind Khan.
Space Seed - S1-E23
Continuity mistake: Khan's hands switch positions several times on the table between quick cuts as he and Kirk talk.
Continuity mistake: As Veena (as the Orion Slave Girl) dances, the water in the pool is still, then in the Observation room, as Kirk and party watch, the water is disturbed. A moment later, it's flat calm.
Continuity mistake: The first time we see the ship travelling at Warp Nine, it is moving in a level, straight path. Next time, the rear end is elevated above the line of flight. The next time, it's moving in level flight again.
Continuity mistake: As Gary Seven starts to talk to the computer, it has a light gray exterior. When it first talks, the trim turns purple, then it's back to light gray.
The City on the Edge of Forever - S1-E29
Continuity mistake: When trying to catch McCoy, Kirk's pants get dirtied. After coming out of the Guardian's time portal in the Depression, his pants are clean.
Continuity mistake: The second time McCoy is shown in the Sickbay, he is first shown sitting and writing. A moment later, he's standing bent over the terminal.
Continuity mistake: In the finale of the fight between Kirk and Finney, Kirk's shirt is torn, exposing his right shoulder and arm. As Kirk (the stunt double) goes for the knock out blow, the shirt is only a little torn in the front. Then the close up on Kirk catching Finney, his shoulder is exposed again.
Continuity mistake: In the dining hall, Korab leans over to listen to his cat. As he does, his right hand is at seat level. A second later, his right hand is up by his shoulder. (00:22:20)
Continuity mistake: In most shots, the Constellation's impulse engines are lit up orange, but when moving to meet the Enterprise, they're not lit up, though the ship is moving.
Continuity mistake: Spock nears the command chair, where a seated Decker is leaning on the left armrest. A second later he is leaning to the right.
Continuity mistake: An Orion spy (disguised as an Andorian) attacks Captain Kirk in the corridor on Deck 5 and plainly stabs Kirk in the back on the right side. As he staggers to his feet, Kirk first reaches to the wound with his right hand, indicating that it is, indeed, on the right side of his back. He then reaches far across his back with his left hand to touch the wound, and we see blood on the back of his hand (but not on his sleeve). So, it is visually established that the wound is on the right side of his back. But, a few moments later in SickBay, Dr. McCoy announces that Kirk's wound is a "puncture to the left lung." Then, later in the episode, Kirk his holding his left arm as though he is suffering pain on the left side.
Continuity mistake: The chain symbol on Kirk's shirt goes from dark to light and back several times.
Continuity mistake: Kirk is holding the communication device out to his right from his view of the Companion and Cochran's, but the next instant shot shows Kirk holding the device close to his chest as he speaks with the Companion.
Continuity mistake: The designs of the fabric the Companion holds up to view Cochran are different from her view versus the view from Cochran's.
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.