The One With Phoebe's Ex-Partner - S3-E14
Visible crew/equipment: Just after Chandler says "I'm the smallest person in the world", and Joey comes out of his room, check the top left of the screen - you can see a boom mic track Matt LeBlanc across the set, and the bottom of some stage lights in the middle. (00:14:40)
Chosen answer: Colleen Mahan and Eric Goldberg also work on the show they are assistants to Kevin Bright, Marta Kauffman and David Crane.