Continuity mistake: When Toby is walking back to his office from the press room with his ex-wife, the ex-wife's tag and chain keeps changing through the entire sequence. Sometimes it's over her jacket and the tag's just hanging or it's under the jacket and the tag is sitting just inside her jacket.
Post Hoc, Ergo Propter Hoc - S1-E2
Continuity mistake: After President Bartlett sits down (while speaking to CJ and the staff) he removes his glasses. The shot then changes to one from his back where he's wearing glasses. When the angle changes to the original, he's not wearing his glasses again. (00:06:30)
What Kind of Day Has It Been? - S1-E22
Continuity mistake: When the shooting starts, CJ is seen being pushed down by a Secret Service agent, and a second later she is seen being pushed down by Sam.
A Proportional Response - S1-E3
Continuity mistake: When Leo asks Chairman of the Joint Chiefs Admiral Fitzwallace about the optics of hiring Charlie, a black man, to carry the president's bags, Fitzwallace's ribbons on his Navy uniform are upside-down. This mistake is very visible because he has two ribbons on the bottom when there should always be three. On his way out the door, there is one shot where Fitzwallace's ribbons have been fixed, but then as he walks out the door his ribbons are upside-down again. (00:25:50 - 00:27:10)
A Proportional Response - S1-E3
Continuity mistake: The president is snapping at everyone while looking for his glasses. Newcomer Charlie addresses Bartlet, who turns and takes off CJ's glasses he'd been trying on. Everybody freezes in surprise at Charlie's interruption, including Bartlet who can be seen holding the glasses away from his body. In the immediate next shot, Bartlet can be seen on the monitor still wearing CJ's glasses, and then interrupts Charlie while removing the glasses once more. (00:33:20)
Continuity mistake: When Josh and Leo are discussing Leo's alcoholism Josh refers to Leo as being "Boston Irish-Catholic" but in several other episodes it's mentioned that Leo is from and grew up in Chicago.
Let Bartlet Be Bartlet - S1-E19
Continuity mistake: When CJ leaves Toby's office and Josh sits town on the couch next to Toby she closes the door as she walks out and we can hear it close. But the camera switches to a different angle as Josh sits down and the door frame is still in picture and is open as we hear the sound of it closing the door frame is still open. (00:20:40)
Take Out the Trash Day - S1-E13
Continuity mistake: This episode takes place in early 2000. 7 or 8 months before the midterm. When Bartlet tells C.J. to drawer the sex education report until after the midterm she exclaims, "next year?"
Take Out the Trash Day - S1-E13
Continuity mistake: This episode takes place in February or March of 2000. Josh and Donna have worked in the White House for 13-14 months, but in the beginning of the episode Donna is asking Josh what 'take out of the trash day' is, when she has been working in the White House for many, many Fridays.
He Shall, from Time to Time - S1-E12
Continuity mistake: When Abby kisses Jed as he's falling asleep there is a change in shot perspective; Abby's hand is suddenly on Jed's chest and the bed sheets move at least a foot towards his head. (00:12:00)
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.