Character mistake: When Hank is brought to the hospital with gunshot wounds, the ambulance and its two EMTs are met outside by two doctors. One doctor says "Let's get him two grams of oxygen. What's his hemoglobin?" This episode's technical adviser was perhaps away for this scene. How much exactly is two grams of oxygen? Orders for administering oxygen would be given in liters, such as two liters per minute (LPM). The line is presumably meant to be 'two liters of oxygen'. (00:02:25)
Character mistake: When Bill mentions to Sophie-Anne that drinking the maenad's blood poisoned him, she says that vampires can only feed off human blood. However, across the show, we've seen vampires drink from fairies, werewolves and even the blood of other vampires, like Lilith's blood. (00:05:50)
Character mistake: When Kim is trying to convince Lisbon to help the FBI on their case, she says Jane stopped the ten-year reign of a mass murderer. Red John was a serial killer, which, by the FBI's definition, is a criminal behavior distinctly different from mass murder; he may have had a large number of victims, but he killed them either one or a couple at a time, with a cooling-off period in between, not all at once.
Character mistake: Tig gets bit on the right butt cheek. Tara tells Chibs to give him a local, which is a numbing injection so she can stitch him up. Problem is that Chibs does the injection in the left butt cheek. You are supposed to give the injection close to the wound to numb it before stitches.
Character mistake: When Will tries to quote the law to the barman, he states that the group must be "accompanied by an adult" in order to drink alcohol with food. However, since he just served Jay, he believed Jay was an adult; and Jay is accompanying the group. Both Will and tha bartender miss this.
Character mistake: When Walter is saying his father was a scientific pioneer at the university of Berlin, Peter reacts by saying: "Yeah, I know. Who came here in 1933, which is long before the Nazi's ever took power." In fact it is EXACTLY when the Nazi's took power: 30 January 1933. (00:19:00)
Character mistake: When the boy is brought to camp that was shot, the Corpsman repeatedly states "he's been zipped by 5.56, Marines shot this boy." It was then assumed that Trombley shot the boy with his M240 SAW. The M240 SAW is chambered in 7.62 x 51mm. Either the Corpsman is incorrect or Trombley didn't shoot the boy.
Character mistake: Upon finding the Spanish flu virus missing, Hardison freaks out about it killing 50m people 100 years ago, saying it would be even more deadly today due to the higher population. There's no reason to think so - the death toll in 1918 was massively exacerbated by the aftermath of WWI. Not to mention today we have vaccines, plus most deaths then were actually caused by bacterial pneumonia, which today is easily treated with antibiotics.