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)
The Gamesters of Triskelion - S2-E16
Visible crew/equipment: As Ensign Haines reports to Spock, the shadow of the camera mostly shades her, then it plays over McCoy.
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)
A Piece of the Action - S2-E17
Visible crew/equipment: When Kirk and Spock pull up after their first car ride, a boom microphone is visible in the reflection from the passenger-side spare-tire cover, which is chromed. As Spock gets out, the mic moves away.
A Piece of the Action - S2-E17
Visible crew/equipment: As Kirk comes around the front of the car in front of Krako's headquarters, another boom mic is reflected on the fender.
A Piece of the Action - S2-E17
Visible crew/equipment: As Kirk first drives the car, the camera is reflected in the car's chromed radiator.
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: When Scotty joins Thalassa while she's working, she asks if he has "prepared the megaton hydrocoils," and the shadow of the boom mic can be seen moving at the top of the screen. (00:33:20)
Visible crew/equipment: After Melakon shoots at the curtained window and kills John Gill in the broadcast booth, Isak shoots Melakon, then when Eneg stops the soldier who points his gun at Isak, the shadow of the boom mic dips into view at the top, left side of the screen. (00:45:50)
Visible crew/equipment: After Kirk and Tracey have fought, Sulu and two others beam down armed with phasers, and when Kirk tells Leslie to free McCoy and Spock, two white tape marks are visible on the floor in front of the actors. (00:45:20)
The Ultimate Computer - S2-E24
Visible crew/equipment: After M-5 fires on the other starships Daystrom speaks to M-5 about the murders, then when Kirk walks over to Daystrom and tells him the M-5 must be destroyed, the shadow of the moving boom mic is visible over Daystrom. The white tape mark is also visible on the floor near Uhura's chair, where McCoy had been standing earlier. (00:42:15)
Visible crew/equipment: After Kirk tells the policeman that he wants to see Merikus and "perhaps" he's a friend, the policemen lock the cell then leave, and when it cuts to a view of the cell from the side as Spock walks over to the steel bars, the overhead boom mic is visible inside the cell, over Spock. It's visible again, with a better view, when McCoy walks over to Spock beside the bars. (00:18:15)
Visible crew/equipment: Set lights are reflected in Spock's tricorder screen before he closes the cover.
Is There in Truth No Beauty? - S3-E5
Visible crew/equipment: Spock and Dr. Jones carry Koldos into his quarters, and when Spock walks over to the wall communicator to contact the bridge, the camera casts a shadow on the wall as it moves closer to Spock. (00:05:20)
Is There in Truth No Beauty? - S3-E5
Visible crew/equipment: At the dinner, when Miranda stands up to leave, there's a visible white tape mark on the floor near her feet. Then, when McCoy makes his exit Kirk reaches for the rose, and there's a better view of the white tape mark under the table. (00:11:50 - 00:13:45)
Is There in Truth No Beauty? - S3-E5
Visible crew/equipment: When Kirk turns to follow Miranda across the arboretum, the camera shadow is briefly visible on the wall at the lower left of the screen. (00:29:50)
Visible crew/equipment: In the very beginning, the boom shadow is visible at the top of the screen as Kirk walks to Spock's station on the bridge. (00:00:30)
Visible crew/equipment: A camera shadow briefly intrudes on the right side of the screen as Kirk asks Mr. Scott about the sensor readings. (00:00:55)
Visible crew/equipment: After Uhura asks McCoy if she'll become like Chekov, McCoy reassures her about finding an antidote. Then, when it cuts to Engineering, there's an actor's black tape mark and a chalk T-mark visible on the floor. (00:38:10)
Requiem for Methuselah - S3-E19
Visible crew/equipment: The monofilament line holding M-4 aloft is visible in the lab when the floating robot delivers the processed ryetalyn to McCoy. (00:17:20)
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.