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.
Answer: Angels themselves may not have genitalia, but their vessels do. Nephilim occur when an angel in a vessel reproduces.
Greg Dwyer