Visible crew/equipment: At the very end, Sarah is alone while she's lying down, but when she has the sudden vision of Laura's necklace being dug up, the reflection of a crew member is visible in the round mirror. (01:32:50)
Visible crew/equipment: When Sheriff Harry S. Truman first leaves the station, film crew are visible as they dolly back across the Ford Bronco. (00:05:55)
Visible crew/equipment: At the diner, when Bobby asks Shelly if she needs a ride home, the reflection of a boom microphone is visible in the horizontal glass mirror behind Bobby (far left of the screen). (00:16:15)
Visible crew/equipment: When Bobby is released by the police, he speaks to his friend in the hallway of the station about the possible identity of Laura Palmer's killer. To avoid eavesdropping, Bobby tells his friend that they should speak outside. As they walk through the glass doors towards the exit, Bobby encounters his father and two other people. Tape markers are visible on the floor placed at their feet. (00:55:53)
Visible crew/equipment: When Sheriff Harry Truman takes the call from Pete Martell at the police station, a reflection of a seated crew member wearing headphones (it actually looks very much like David Lynch!) is visible in the glass divider of the office the Sheriff enters to answer the phone. Clear as day. (00:05:13)
Answer: The answer to pretty much any question beginning with "Has David Lynch ever explained _______?" is: no.