The Magician - S3-E4
Revealing mistake: When Oliver meets Thea at the Grind and Jot Cafe (Which looks unsurprisingly like CC Jitters) you can see the cups on the table are from CC Jitters. (00:20:50)
Al Sah-Him - S3-E21
Character mistake: Diggle turns to Nyssa and says "I think what she's trying to say is, Oliver would never do anything to hurt you, Felicity," incorrectly addressing Nyssa as "Felicity." (00:14:50)
Darkness on the Edge of Town - S1-E22
Character mistake: At one point Felicity says, "There's at least a teraflop of data to go through." Felicity is a computer genius, so she should know that a teraflop is a measurement of processing power, not data storage. She should have said "terabyte."
Factual error: There is no way Laurel Lance would have been allowed on the prosecution team for Moira Queen's murder trial. Due to the facts that she both dated and as a lawyer represented the defendant's son, the defendant's daughter used to intern for her, and her boyfriend was one of the people killed in the Glades, it would have taken all of two seconds for the court to have her removed if she didn't willingly recuse herself, since her presence would be a major conflict of interest.
Character mistake: When Oliver is brought into Fires' tent, he gets pushed into a pole by one of the guards. Take a close look at his handcuffs. They are so loose, he could easily escape from that. Not only that, but no guard who had any training would ever put handcuffs so loosely on someone they would treat as "hostile".
Factual error: When Oliver is hunting Prometheus, they come face to face. Oliver fires an arrow, which is tracked in slow motion before being split by one of Prometheus' throwing stars. Problem is that Oliver's arrow is, well, flying straight as an arrow. But in reality, when you film an arrow in slow motion, they flex and wobble, and definitely wouldn't fly like the one shown on screen.
Restoration - S4-E3
Factual error: Felicity apparently extracts DNA from the tooth of one of Damien Darhk's men. She then realises that the DNA lacks "half of the genetic markers" by looking at an optic microscope. Skipping the fact that this sentence makes absolutely no sense whatsoever, you certainly cannot analyse genetic markers by simply looking a tooth with an optic microscope. (00:11:05)
Suggested correction: No science behind this statement.
What is it supposed to mean?
Left Behind - S3-E10
Continuity mistake: In the previous episode Ra's al Ghul stabs Oliver through his chest, just below his left pec. When he pulls out the sword, a wound is visible. (However, seconds later, the wound is absent - different mistake). In this episode he is shown with a wound much lower (in his lower abdomen) and also later, with a bandage around his waist instead of his chest. (00:09:30 - 00:41:30)
Factual error: In this episode Barry uses rat poison to save Oliver, from a poison that coagulated blood. Though rat poison contains anticoagulants like Warfarin, this is medically wrong because, It takes at least 1-3 days for Warfarin to be effective and it may even cause excess of coagulation during this time. It could never have saved Oliver instantaneously. What Oliver needed was heparin. So Barry in real world instead of curing Oliver might just have made him much worse.
Factual error: Felicity tracks the abducted team members to latitude and longitude values that are negative, which she and others present regard as impossible results until they realise the captives are in outer space. In actuality, south latitudes are conventionally represented as negative, as are west longitudes; and negative values would not convey information about an outer space location, which would instead be referenced with celestial coordinates. (00:36:50)
Continuity mistake: When Oliver shoots Ted with an arrow, Ted falls down on the ground. The position of the arrow keeps changing from being perfectly in the center of the chest, to a few inches off-center, depending on the angle.
Visible crew/equipment: When Oliver jumps out of the window of Adam Hunt's office, you can see the safety rope at the bottom.
Continuity mistake: In the scene in the garden where Oliver and his sister stand by the headstones, Robert Queen's birth date is carved into the stone as 1958. This conflicts with the news report at the beginning of episode 1 when his birth date is shown as 1948.
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).
Visible crew/equipment: When Slade brings the drink in the forest (referring to Billy Wintergreen), you can see shadows of people walking upstairs in the background behind a big white curtain. (00:07:30)
Suggested correction: It's not a crew member, it's wind.
Factual error: General Shrieve's rank is on upside down. (00:04:20)
Factual error: The highest-ranking military officer in the DIA (Defense Intelligence Agency) is the director, which is a three-star position. John's stepfather Roy Stewart would not be a part of the organization, let alone answering to superiors in the organization if he was a four-star general.
Left Behind - S3-E10
Visible crew/equipment: During a flashback with Oliver and Maseo, they are on a rooftop trying to break in to the building next door by means of the pulley system on the bow. Maseo is shown lining up a shot with his sniper and in the background one can see a crew member's face looking over his shoulder. (00:13:30)
Suggested correction: There are other ARGUS agents with Oliver and Maseo. That is one of them.
Continuity mistake: Ra's al Ghul stabs Oliver through his chest, just below his left pec. When he pulls out the sword, a wound is visible. However, seconds later, the wound is absent. (00:41:05)
Crisis on Earth-X, Part 2 - S6-E8
Deliberate mistake: During the big battle, Arrow is knocked down and when he opens his eyes, the reflection in his eyes is tilted over to give the sense he's seeing things sideways. But the reflection should still have shown the proper orientation no matter what orientation his eye was at. Think of looking into a mirror and then rotating the mirror to the side, the reflection wouldn't rotate.
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