Visible crew/equipment: Carter is told about the multiple rectal exams due to food poisoning. It then cuts to admitting, and just as the person at the desk bends over, on the glass partition we can see the reflection of the boom operator (wearing a white T-shirt) holding up the boom pole (not the maintenance worker standing on the ladder).
24 Hours (2) (a.k.a. The Longest Day (2)) - S1-E2
Visible crew/equipment: After Peter examines the man with a ruptured aortic aneurysm, he exits the room. Peter tells Susan that this man needs immediate surgery, and in the shots facing the exam room during their conversation, we can see the reflection of the moving boom mic on the door's glass, at the top of the screen.
Answer: It was in "Chaos Theory" which is the first episode of season 9 (time code 00:13:55).
Super Grover ★