Visible crew/equipment: As Fox is being led into the jail, when Scully says, "Mulder" the boom mic is at the top of the screen, while she's walking towards him. (00:20:30)
Never Again - S4-E13
Visible crew/equipment: When Ed turns to go into the office, you see the reflection of the boom mike on the glass window. (00:05:30)
Visible crew/equipment: When Scully asks Fox "Do you know what day it is?" the boom mic drops down at the top of the screen. (00:04:50)
Visible crew/equipment: During the scene when Mulder, Scully and the deputy approach the farmhouse there is a moment when Scully walks up to a chicken coop and a boom microphone with a fluffy wind cover on can be seen coming up from the bottom of the screen (Underneath Scully). (00:30:35)
Answer: As he stated many times throughout the series, Mulder needed Scully to be sober and skeptical. Whenever Scully's skepticism wavered and she started questioning her own rationality, Mulder would try to restore her sense of skepticism, because he needed her to be clear-thinking.
Charles Austin Miller