Continuity mistake: Oliver chops off Malcolm's hand to end their duel. When Oliver hands the ring over to Nyssa you can see Malcolm lying in the background where he has been cut down with two hands intact, and the cut off hand nowhere in sight.
Arrow (2012)
1 mistake in Sins of the Father
Starring: Katie Cassidy, David Ramsey, Stephen Amell, Colin Donnell, Emily Bett Rickards
Lone Gunmen - S1-E3
Oliver Queen: I'm having some trouble with my computer and they told me you were the person to come and see. I was at my coffeeshop surfing the web and I spilt a latte on it.
Felicity Smoak: Really?
Oliver Queen: Yeah.
Felicity Smoak: Because these look like bulletholes.
Oliver Queen: My coffeeshop is in a bad neighbourhood.
Trivia: Although Laurel is a couple of years older than Sara, Katie Cassidy is only about a month older than Caity Lotz.