Other mistake: Before the security guard is killed, he turns around and faces the direction of the camera. He is killed, and the camera backs up to reveal 6 men standing there. The security guard would have seen the men and he had time to react to them, but did nothing. (00:32:50)
Arrow (2012)
1 mistake in Vendetta
Starring: Katie Cassidy, David Ramsey, Stephen Amell, Colin Donnell, Emily Bett Rickards
John Diggle: The knife.
Oliver Queen: Right. The knife. I got lucky.
John Diggle: That was a kitchen knife. It wasn't even weighted properly and yet you threw it with accuracy across a ten foot room.
Oliver Queen: Exactly. I got lucky.
Trivia: Although Laurel is a couple of years older than Sara, Katie Cassidy is only about a month older than Caity Lotz.