Visible crew/equipment: After McCoy examines Charlie and they talk about how Charlie learned to talk by just listening to the ship's tapes, when Charlie stands up the two actors' marks can be seen on the floor - the short one for Charlie and the longer one for McCoy, where they both will stand momentarily. (00:04:56)
Visible crew/equipment: When Charlie catches up with Rand and gives her the present, the microphone can be seen moving around at the bottom of the screen in the shots with both of them. (00:06:48)
Shore Leave - S1-E16
Visible crew/equipment: You can see the shadow of a boom mic moving on a tree just as the Caretaker appears. (00:44:05)
Visible crew/equipment: When the doctor is mixing the drink and Pike gets up off the bed to accept it, an equipment shadow sweeps across the left side of the screen. (00:03:55)
Visible crew/equipment: While Kirk and Spock are being chased, McCoy hears the gunfire so he stands up and walks away from the rock, then just as McCoy stops to use his communicator to contact Enterprise, the ground microphone is visible at the bottom, left corner of the screen. (00:02:30)
Visible crew/equipment: After Kirk hits Kras with an arrow Spock's arrow hits a Capellan on the cliff, and when the Capellan falls into the bush, a crew member wearing sunglasses and a white T-shirt is visible at the left side of the screen. (00:43:50)
Visible crew/equipment: After Garrovick is relieved of his duties, Kirk tells McCoy and Spock to make comments and recommendations in their reports, then Garrovick returns to his quarters. Just as Kirk exits the turbo lift on the bridge, the boom mic is visible at the top, left side of the screen. Then when Kirk apologizes to Scotty, in the next wide shot two pieces of filming equipment are visible at the top of the screen. (00:17:20)
Visible crew/equipment: As Kirk gives orders to Nomad to lower screens for Spock to examine it, the shadow of the boom mike is seen toward the top of the screen behind Nomad. Also, the wire holding Nomad up is visible.
Visible crew/equipment: When Dr. Van Gelder tells Kirk that he wants asylum and his word that he won't be taken back to Tantalus, in the wideshot from behind Kirk as he moves to his right the two tape marks can be seen on the floor beside Van Gelder's feet.
What Are Little Girls Made Of? - S1-E8
Visible crew/equipment: After Roger's introduction, when Kirk tries to communicate with Rayburn for security confirmation and also when Andrea walks over to Kirk, a few actors' tape marks can be seen on the floor and rug.
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)
Visible crew/equipment: After Uhura tells Kirk that "Captain Ramart of the Antares is on D channel," Kirk and Charlie head to the bridge, and when it cuts to Uhura the actor's tape mark can be seen on the floor behind her, where Charlie will stand when he steps out of the turbolift.
Visible crew/equipment: After the Klingon vessel's attack on the Enterprise, while returning fire just as Kirk orders to maintain firing range at 100% dispersal pattern, the set's unfinished wood plank with grey paint drip marks can be seen at the bottom of the screen. Additionally, at the end when Spock goes to stand beside Kirk's chair (also when he walks away) the actor's mark can be seen on the floor by Spock's feet.
The Gamesters of Triskelion - S2-E16
Visible crew/equipment: When Chekov's drill thrall sits down and nuzzles up to him in his cell, the boom shadow is visible on the wall at the upper left corner of the screen. (00:14:50)
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)
Visible crew/equipment: When Kirk is thrown into jail with Spock you can see the movement of the entire blue crash mat used to break his fall.
A Piece of the Action - S2-E17
Visible crew/equipment: After the Krako drive-by shooting, Kirk, Spock, and McCoy are forced to walk down the street, and when a woman asks about the crummy street lights, multiple chalk T-marks are visible on the ground. (00:06:20)
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)
Operation -- Annihilate! - S1-E30
Visible crew/equipment: When Spock and McCoy walk into Kirk's quarters, in the wideshot the white tape mark can be seen on the floor under the desk at Spock's feet, before Spock requests permission to beam down to the planet, and can be seen again when Kirk stands up.
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.