Continuity mistake: When Jack tries levitating a pencil, the pencil completely vanishes after he sets it down again.
Continuity mistake: When Sam gets the skeleton heads out of the back of the car, he brings the box in his arms long ways, but when the shot goes back to him it is turned the other way. (00:22:50)
Continuity mistake: When Sheriff Mills and Bobby are talking about transferring Rufus, her lapel goes from being under her seatbelt to over several times in subsequent shots.
Continuity mistake: Elliot Ness and Dean are in his car waiting for the god of time. Elliot takes out his flask, takes a drink, offers some to Dean. Dean declines and Elliot puts the flask back in his pocket. The next shot Elliot is taking a drink again without pulling it back out of his pocket. (00:35:00)
Continuity mistake: When Bella first counts her cash, the bills are all in hundreds. The camera changes angles and the bottom bill becomes a fifty.
Bloody Mary - S1-E5
Continuity mistake: When Jill's friend is saying how Jill died and mentions her eyes, she has her hands lowered in one shot but raised in the next. (00:16:11)
Continuity mistake: When Dean says he's going to talk to Amanda to get a grip on her mental state he has his head back on the seat and is looking straight ahead. When the shot changes he's now looking at Sam. (00:27:20)
Keep Calm and Carry On - S12-E1
Continuity mistake: Mary does not recognize adult Dean and claimed that her Dean is 4 years old. In Season 1 Episode 9: Home, she recognized adult Dean and Sam.
Continuity mistake: In this episode, Dean says he was born in 1979. In the first two seasons, in the flashback to their mother dying, that's in 1983 which would make Dean 4 years old. He's definitely not 4 years old in the flashbacks.
Answer: Angels themselves may not have genitalia, but their vessels do. Nephilim occur when an angel in a vessel reproduces.
Greg Dwyer