Continuity mistake: In 'The Janus List' (324), when David gets mad at Colby for being a spy, he says "You're not a spy, you're a damn traitor". But, in 'Trust Metric' (401), when Don is reviewing the tapes of Colby's interrogation, David says "You're not a damn spy, you're a traitor".
Continuity mistake: When Charlie explains that his map was generated by an equation he writes the equation in abbreviated form on the whiteboard, and also when he writes the equation for the probability of winning the lottery, in following shots the handwriting changes and some of it vanishes and reappears.
Visible crew/equipment: When Don talks to David about his priorities and the importance of finding Rachel Abbott's car, right after David tells him that the car is not turning up, we can see the reflection of the moving boom pole and mic on the glass door.
Visible crew/equipment: After Charlie tells Alan that he and Amita have a lot of work to do and that Alan's hovering over them, when Alan walks away from the table we can see the actor's tape marks on the floor where he had been standing, and also more blocking tape on the rug and kitchen floor.
Continuity mistake: While Don's at the parking garage with Rachel Abbott's car he realises that the killer had been watching Karen Silber's house, and when they rush off to her house there are white security bars on the windows and front door in the long shot and also later in the news footage, but when they're at her house none of those bars exist and the shrubbery also differs.
Factual error: When Charlie describes the Uncertainty Principle, he is actually describing the Observer Effect, a concept commonly mistaken for the Uncertainty Principle. The Uncertainty Principle actually states that the position and momentum of a particle cannot be accurately known simultaneously.
Continuity mistake: While the mother is driving her children to school in a minivan, both the driver's seat and the front passenger seat change from having the headrest/whiplash protector being attached to the seats (non-removable), to having the adjustable kind that have been removed.
Continuity mistake: When Charlie Epps is writing a quadrillion on the whiteboard, the writing alternates between shots. Most noticably when he first writes it down, there is a significant downward tendency of the 000 groups. In the next shot, they are pretty much horizontal. Also the shapes of the commas alter.
Visible crew/equipment: After Charlie comes up with the idea of creating a false master key and designing the lock that it opens, when it cuts to them back at the office the yellow T-mark can be seen on the floor by David's foot.
Character mistake: In the epilogue, Charlie illustrates the relationship of mathematics to real life by discussing the golden ratio and its presence in a host of real-life situations, including the shape of a nautilus shell and the distribution of petals in a flower. These claims are disputed by some mathematicians (see http://en.wikipedia.org/wiki/Golden_ratio#Nature), and the one about the nautilus shell one is untrue (see http://en.wikipedia.org/wiki/Golden_spiral#Spirals_in_nature). It's possible Charlie is just repeating what he has read or heard without investigating it for himself, but this is uncharacteristic of him.
Factual error: The Secret Service agent says the bills are counterfeit because you can see the watermark under a uv light, which is completely wrong. The uv reactive strip is not a watermark, it's a plastic strip embedded between the two layers of the bill and fluoresces under uv as a security measure. In older bills, it glows blue as in the film. In newer ones, it glows yellow to orange and is on the right half of the bill. A fake bill would be the one that does not glow. (00:07:20)
Visible crew/equipment: After the Secret Service agent calls the counterfeiters "our guys," when it cuts to them back at the office at least three actors' T-marks are visible on the floor.
Visible crew/equipment: When Don and David chase down Jose Salazar and get him down on the ground to cuff him, a crewmember (presumably the second cameraman shooting Jose's low angle closeups) is lying on his back behind David.
Continuity mistake: When Jose Salazar is eventually arrested, he is knocked to the ground, and handcuffed behind his back. However, the next shot shows Jose pushing himself up with his own hands. His hands are then behind his back in the following shot.
Dirty Bomb - S1-E10
Factual error: Season 1, Episode 10, "Dirty Bomb": The opening figures refer to "500g of Nuclear Material." These are the wrong units to determine the hazard level in a radiological sample. The "Curie content" describes, roughly, how much radiation will be given off, and is not tied directly to the sample's mass. 500g of Cesium-137 (the isotope being discussed in the episode) could well be less radioactive than 1g of a different isotope.
Dirty Bomb - S1-E10
Continuity mistake: When Charlie is writing the result of the calculation for the first time he writes "25,600", but when the shot changes he finishes writing "25600", without a comma.
Continuity mistake: When Charlie is comparing a computer wipe to a data scrubber, he first crosses out the equation"E=MC2" with a magic marker, beginning mostly with uniform, vertical lines, and then lightly scribbled. However, in a later shot in the sequence, the cross-out is different, being mostly scribbled, with few vertical lines.
Noisy Edge - S1-E12
Factual error: In the beginning of the episode, Charlie is stating that "there is always a solution" and "if there's any limitation it's got to be in the mathematician, not the math". Unfortunately, according to Kurt Godel's incompleteness theorems, this is not true. Simply put, there are mathematical problems that cannot be proven/solved.
Continuity mistake: Throughout the series when Megan Reeves is wearing long sleeves they tend to go up and down in split-second speed between shots.
Soft Target - S2-E6
Character mistake: On the roof, Don and the other agents have their weapons drawn on James Grace, who is holding Houseman hostage with the fake bomb. Once Grace is taken away, the threat is gone. But Don still has his gun pointed at Houseman, with his finger on the trigger. Houseman, while Don might think is a jerk, was innocent of any crime. There's no reason an agent like Don would have his gun pointed at him.
Answer: Craps is a casino game where players bet on the outcome of a dice roll. It deals heavily with probabilities and is a favorite of math experts like Charlie. Whatever the odds, though, your chances of winning are much greater than winning the lottery.