Continuity mistake: In season one, Sara is a brunette in Oliver's flashbacks. In this season's flashbacks, she's a blonde (most noticeably the ones aboard the Queen's Gambit).
Continuity mistake: When Oliver tries on his mask for the first time, he is not wearing eye make-up. When the mask is on in the next shot, he suddenly is.
Continuity mistake: When Bronze Tiger is stealing the prototype earthquake device, when the truck is leaving Merlin's garage, the street shown has street lights and a factory building, not a country estate driveway. (00:17:10)
The Man Under the Hood - S2-E19
Continuity mistake: In the first shot of Thea running out of Slade's car, she closes the door. In the second shot, you can see the door of the car open. (00:02:05)
Suggested correction: When Diggle is walking away from Felicity, he is still talking to her but it looks like he is talking to Nyssa.
Stephen Edmonds 1
People have already tried to correct this mistake. It is valid. In the scenes prior, Nyssa says Oliver will do what it takes to kill her and Oliver says "tonight, Nyssa Al Ghul faces justice." Nyssa is there to bring the team the news that Oliver is going to try to kill her. Felicity says "Oliver wouldn't", meaning Oliver wouldn't try to kill Nyssa. Diggle says "I think what she's [she being Felicity] trying to say to say is that Oliver would never do anything to hurt you" [you being Nyssa whom Oliver is going to try to kill]. He is meant to say "Nyssa." Otherwise the entire line means Nyssa or Laurel are there to convince Felicity that Oliver would never do anything to hurt Felicity.
Bishop73