Bloody Mary - S1-E5
Continuity mistake: When the real Jill is being Killed the blood lines from her eyes go from smeared to "clean" lines instantly. (00:14:20)
Continuity mistake: At The End of this episode Dean suggests they go to the Grand Canyon because they have never been, later in the series they talk about John taking them when they were little.
Continuity mistake: In the scene where the passengers board the plane at the beginning, the aircraft is a Boeing 737, noticeable by the crew jumpseats located by the entrance door. But the first scene you see where the aircraft is in flight, the aircraft changes to a Widebody Airbus, possibly an A310, noticeable by the different style of winglets that Airbus uses compared to that of Boeing. (00:02:15)
Continuity mistake: Season 6 Episode 15 'The French Mistake': When Sam and Dean are first talking to Misha, the collar of his shirt is tucked into his jacket, as normal. However it suddenly is sticking out over the top of his coat, then changes to being tucked in again, with no time for him to have changed it himself.
The Benders - S1-E15
Continuity mistake: When the Deputy handcuffs Dean to the car door handle, he uses a small radio/cell antenna from the car to pick his handcuff lock (attached to his wrist), just as the bad guys walk toward the car. When the bad guys get to the car Dean is gone and so are the handcuffs (including the cuff that was attached to the door handle). Dean did not have time to pick both handcuff locks.
Mannequin 3: The Reckoning - S6-E14
Continuity mistake: When the guys tip Rose into the grave, her eyes are open, but as she lands and dirt falls over her face, her eyes are closed. A dead person's eyes don't close on their own. (00:25:20)
Bloody Mary - S1-E5
Continuity mistake: In the scene where Jill is looking at her 'Bloody Mary' reflection, the lines of blood coming from her eyes go down and straight over her mouth (because she hasn't smeared them like the real Jill has). But as she begins to talk, the lines switch from being over her mouth to off to either side of her mouth and back multiple times. (00:14:20)
Continuity mistake: In the opening scenes, Vamps drags Chrissy Chambers through the shattered passenger-side window of their crappy vehicle, but by Sam and Dean's arrival, that window is magically unbroken. (00:02:30 - 00:15:55)
Continuity mistake: When Sam and Dean break into Lori's dorm, Sam notices (and the camera pans towards) an open window. The camera then cuts to Dean. When the camera cuts back to Sam the window is closed. We watch Sam open the window and climb through it.
Continuity mistake: In the very first scene with Lori and Rich kissing in Rich's car, Lori's seatbelt is shown to be over her arm close to her shoulder. The camera cuts to Rich and back and the seatbelt is now behind her arm and lower without her having moved at all.
Continuity mistake: When Sam approaches Pamela to give her a hug, you see his hand on her arm. In the next shot he is still walking towards to her and his arm is hanging at his side.
Taxi Driver - S8-E19
Continuity mistake: When Crowley comes to the ship and finds Kevin Tran he blew out the glass on the ship to get rid of the sigils. When Sam and Dean get to the ship to check on Kevin, and they notice he's gone, all the glass isn't broken and the sigils are still there.
Bloody Mary - S1-E5
Continuity mistake: When Sam is looking at the mirrors with night vision, we see him pause and say to Dean "Look at this." The camera then cuts to an extreme closeup of the camcorder screen and the image on the screen is different to what was on there before. (00:18:15)
Continuity mistake: At the start as we see the victim on the plane, we see a blonde woman sat in the middle seat 2 rows in front of his row. When he gets up to stretch his legs, this blonde woman has now changed to a Chinese one. (00:02:45)
Continuity mistake: Dean circles the newspaper article on Sophia Carlton. When he hands it to Sam the circle is different. (00:03:20)
Continuity mistake: When the first victim stands up to stretch his legs, he grabs the seat in front of him and his arm is bent. When the shot changes his arm is now straight and he's holding the middle of the seat not the edge. (00:03:00)
Continuity mistake: Season 1 episode 2, Wendigo conflicts with this episode. Originally the wendigo information is printed on the left-hand side of the journal. On the right side is loads of symbols and text. Here the "same" page featuring the wendigo can be seen when Dean and Sam are searching for the asylum information but it's different.
Continuity mistake: As Sam is looking for the next victim in his visions, she walks by with her baby in a stroller. The baby is a completely different looking doll the first two times shown, but is blue-eyed Rosie when Sam approaches and interacts with her. (00:12:30)
Continuity mistake: After Dean zaps the TV with the remote, he lowers his right arm. The next shot behind Dean's right side shows him lowering his arm again.
Answer: Angel blades come from angels. It's their angelic magic that makes it special. Therefore, an archangel blade is made magical with the powers of an archangel. They couldn't have just created one or used one, as none of them are archangels.