Visible crew/equipment: When Mario is telling Luigi about getting a call from the café for the plumbing job at the start of the film, watch the cabinet with the glass doors behind Luigi. At one point, you can see the reflection of a crew member in a short-sleeve shirt for a few seconds.
Visible crew/equipment: When Elijah Wood is being carried down the stairs, the shadow of a boom mic can be seen on the back wall just before the camera pans to look down the stairs.