Visible crew/equipment: Before The End of the episode, Sam and Dean are thanked by the sheriff's daughter and her son. When Sam and the mother are left alone, his microphone wire is visible when he stretches. (00:41:00)
Visible crew/equipment: When Sam tells the little girl to take her brother outside. The little girl runs out with her brother and Dean asks the little girl where Sam is, Dean runs to the Impala and grabs a shotgun. When Dean is running to the house, he runs on the lawn and you can see the shadow of the camera man running with Dean at the bottom of the screen.
Visible crew/equipment: When Dean thanks the professor before leaving the room, you can see the second camera pan down on the left side of the screen before it cuts to that camera's view. (00:28:40)
Visible crew/equipment: At the start of the episode, the couple comes out of the car and when it pans to show the orchard, a shadow can be seen walking in the lights.
Hell House - S1-E17
Visible crew/equipment: When Dean, Sam, Ed and Harry have just shot Mordechai, the cameraman's arm is visible on the right-hand side of the screen. (00:33:30)
Hell House - S1-E17
Visible crew/equipment: Right before they light the house on fire, the shot cuts the to the hell hound guys and a cameraman is running up to them on the right. Not just an arm - his whole body, including the camera.
Visible crew/equipment: When Sam and Dean are talking to Bobby about to leave after exorcising Meg, in the bottom right corner of the screen a cameraman's arm and camera can be seen. (00:17:10)
Visible crew/equipment: While Sam Bobby and Dean are talking you can see in the bottom left-hand side a person sitting looking at a camera. (00:17:28)
Visible crew/equipment: In the scene before Dean makes the promise to Sam, as the camera pans along the side of the Impala, in the rear of the car, you can see the dolly track that the camera runs along.
All Hell Breaks Loose: Part 1 - S2-E21
Visible crew/equipment: When dean and Bobby drive to the burnt down road house, you can see the boards holding up the wall in the set at the old front door, the boards are set at a right angle to hold the wall up but definitely wouldn't be there it the place was intact.
What's Up, Tiger Mommy? - S8-E2
Visible crew/equipment: You can see the crew member's leg go up in the air, and he catches Sam as he runs down the stairs. (00:36:00)
Answer: Angels themselves may not have genitalia, but their vessels do. Nephilim occur when an angel in a vessel reproduces.
Greg Dwyer