NSF Thurmont - S6-E1
Continuity mistake: When C.J. and Toby discuss and have a snack in Toby's office while the president waits for Chairman Farad's call, at some point C.J. talks while holding the pack of peanut butter crackers in one hand, and one that she is about to eat in the other. Less than a second and a half later, the camera is back on her, but she is now seen holding a bottle of water that was on the table only seconds before. (00:24:25)
NSF Thurmont - S6-E1
Deliberate mistake: While a nice approximation, the helicopter used as 'Marine One' is significantly different (and much smaller) than the real ones used by the real White House (http://www.minihelicopter.net/Marine1/MarineOne.jpg). (00:38:10)
NSF Thurmont - S6-E1
Continuity mistake: Leo enters the situation room and is told the "planes are on the deck". He watches a video feed as a plane is launched from the USS Lincoln. The S3-B Viking is seen approaching one camera (single vertical tail fin, wing-mounted engines), then from another angle, we see an F-14 Tomcat lifting off (dual tails and fuselage-mounted engines) and moving away from camera. This is supposed to be live video, and it isn't possible two different jets are launching from the same carrier at the same exact moment, so it can only be a bad choice of stock footage by the show's makers. (00:38:55)
NSF Thurmont - S6-E1
Continuity mistake: When Donna is writing on a pad to Josh when awaiting surgery, she first writes "Nice hat!!!" A few seconds later we see the pad again, and the exclamation marks have disappeared. Shortly after, they are back.
NSF Thurmont - S6-E1
Visible crew/equipment: When the motorcade is driving up you can see part of the film crew in the background.
NSF Thurmont - S6-E1
Continuity mistake: When Kate is in Leo's office with the red folder on her lap, the position of her hands changes depending on the camera angle. Viewed from in front both hands are gripping either end of the folder, from behind her hands are clasped together and rested on top of the folder.
Other mistake: During the peace talks between the Arabs and Israelis CJ tells the press that the group had Maryland Crab Cake for lunch. Jews would not eat crab and some Muslims also would not.
Factual error: Near the end of episode 1 in series 6, General Alexander is briefing Leo, and the screen shows the Alpha strike headed east toward Syria from the USS Lincoln, which is depicted as being in the Mediterranean. In episode 2, he briefs the press, telling them that the strike was launched from the Lincoln in the Gulf.
In the Room - S6-E8
Continuity mistake: When the senator talks to Josh, he says he's going to investigate again why Margudian went to play golf with a navy helicopter, and Josh says that was a year ago, but Margudian was in the first/second season. That's a lot more than a year.
Faith Based Initiative - S6-E10
Other mistake: In the flashback episode where the early days of the first Bartlet campaign are shown, Toby is "teaching" C.J. the proper technique for passing a basketball, something she is not very good at. Yet in this episode, when C.J.'s sexuality is questioned in the news, her history as a star basketball player in high school and college is revealed.
Continuity mistake: When Kate Harper and Sec. Hutchinson are arguing about the hostages in Bolivia, the digital clocks on the wall behind Kate don't sync properly as the shot switches between the two of them. (00:30:15)
Continuity mistake: As the President leads the staff out of the Oval Office, the rear angle shot shows Kate Harper is ahead of Annabeth Schott. But the angle reverses to show them emerging from the office as Kate is coming around Annabeth's right side to pass her. (00:40:00)
Factual error: When Will comes to Leo's office at the scheduled time of 6PM, the sun is shining brightly through Leo's window. Since this is the day after the State of The Union address which is mid-January, it would already be dark in DC.
Other mistake: All seven candidates appear on stage, however John Hoynes isn't among them. (00:40:45)
2162 Votes - S6-E22
Continuity mistake: Josh and another aide on the Mat Santos campaign are walking up the stairs to go out into a public area, as they reach the top of the stairs and about to go out the door they are not wearing sunglasses as obviously they are indoors, but in the next shot outside they are both wearing sunglasses without putting them on. (00:08:30)
Chosen answer: A really annoying innate lack of sense. My friends and family say the same thing all the time, and I'm endlessly trying to correct them. I think people just don't know any better and (ironically) couldn't care less that they're speaking incorrectly.