Where No Man Has Gone Before - S1-E4
Continuity mistake: After Mitchell relieves him, Mr. Alden walks past Yeoman Smith. As he does, he suddenly disappears as Kirk is sitting in his chair. (00:03:55)
Where No Man Has Gone Before - S1-E4
Continuity mistake: When Kirk exits the turbolift he sits in the captain's chair, and Yeoman Smith stands behind him with barely any space between them, but in the shot facing the main viewscreen Smith is gone, and in the next shot she reappears right behind Kirk again. Smith continues to disappear and reappear in following shots. (00:04:00)
Where No Man Has Gone Before - S1-E4
Visible crew/equipment: As the camera is close up on Kirk, and as he addresses the ship, the shadow of the boom mic plays on Smith's neck. (00:04:35)
Where No Man Has Gone Before - S1-E4
Visible crew/equipment: When Mitchell tells Kelso that Dehner is a "walking freezer unit" we can see wires and other equipment on the floor, in front of the helm and navigation console. (00:05:35)
Where No Man Has Gone Before - S1-E4
Revealing mistake: After the ship enters the galactic barrier, when Kirk orders "navigation on automatic" there are flashes of light, and in a closeup of the first console just to the left of the main viewscreen, we can see the special effects material spread across the panel below the controls, for the fire to burn when it explodes. Then it cuts to the wideshot as a second console (near Spock's station) blows up, but in the background that first console is intact - no fire/damage whatsoever (it explodes again in a following wideshot). (00:10:00)
Where No Man Has Gone Before - S1-E4
Visible crew/equipment: When Dr. Dehner is talking to Gary Mitchell in sick bay, when he grabs her arm you can see the shadow of the boom mic on the door and adjacent wall. (00:19:25)
Where No Man Has Gone Before - S1-E4
Character mistake: When Sulu is explaining the mathematics of Gary Mitchell's powers getting stronger, he says they are increasing "Geometrically", and then uses the popular example of doubling a penny every day for a month. What Sulu is describing would actually be exponentially. (00:24:14)
Where No Man Has Gone Before - S1-E4
Visible crew/equipment: After Kirk's briefing regarding Mitchell's abilities, when Spock and Kirk are alone just as Spock says that they'll never reach an earth base with Mitchell aboard, the boom mic casts a shadow overhead until Spock steps forward, and a bit can be seen again when Spock tells Kirk that it's his only choice. (00:24:50)
Where No Man Has Gone Before - S1-E4
Visible crew/equipment: While Kirk, Spock, and Dr. Dehner are with Gary in sickbay, when Gary makes threatening remarks and gets out of his bed, the shadow of the moving boom mic is visible on the wall at the left side of the screen. (00:28:55)
Where No Man Has Gone Before - S1-E4
Visible crew/equipment: While Kirk is armed with a phaser rifle he quietly moves closer to Gary and Dr. Dehner, but when Gary senses the "foolish man" he causes a boulder to roll past Kirk, and the arm of a crew member is visible behind the boulder pushing it forward. (00:39:40)
Where No Man Has Gone Before - S1-E4
Continuity mistake: When Kirk is fighting Gary Mitchell, his tombstone reads James R. Kirk. Kirk's middle name is Tiberius. Mitchell is a friend of long standing and would not have got it wrong. (00:44:30)
Where No Man Has Gone Before - S1-E4
Revealing mistake: When Kirk & Spock are watching Gary read the pages on the monitor one after the other, look closely: it's the same two pages back and forth.
Where No Man Has Gone Before - S1-E4
Revealing mistake: The readers in Sick Bay are supposed to be display screens, a type of CRT, for reading material. Mitchell turns his off to rest, but the words are still plainly visible.
Where No Man Has Gone Before - S1-E4
Continuity mistake: As Kirk, Spock and Mitchell exit the lift, Yeoman Smith is by the door and begins to follow, and an un-named guy walks by her and into the lift. In the wide shot of the bridge, the actions of Smith and the crewman are repeated.
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.