Abu el Banat - S5-E9
Continuity mistake: When the president is in the oval office with the first lady and they are called by Charlie to receive their daughter Liz, the office does not have a Christmas tree, however, in the next scene when he leaves his grandson to go with Leo and C.J. to the office, the Christmas tree is already set up.
7A WF 83429 - S5-E1
Continuity mistake: When Margaret walks into Leo's office and he sleeps, the screen says it's the sixteenth hour of Zoey's kidnapping. Leo asks Margaret what time it is and she says it's almost 5:00. At the beginning of the episode when Abby and the president talk at the residence, the president says it's 6:30, and the screen says it's the eighth hour of the kidnapping, then if we move another eight hours until we get to the sixteenth hour of the kidnapping, it would be 2:30, not 5:00.
The U.S. Poet Laureate - S3-E17
Character mistake: Jed Bartlett is talking to Leo and Hoynes. He says 'Calvary' instead of 'Cavalry' in the line "Tell Josh that General Pulaski was a Polish Brigadier General who vanquished the Russian and Prussian military then came to the colonies and commanded our cavalry during the American revolution."
Continuity mistake: At the beginning of the episode, while CJ is talking to Sam about getting lost on the way to work, the fishbowl gets turned around mid conversation - the elephant in the fishbowl suddenly faces the other way.
NSF Thurmont - S6-E1
Visible crew/equipment: When the motorcade is driving up you can see part of the film crew in the background.
Other mistake: All seven candidates appear on stage, however John Hoynes isn't among them. (00:40:45)
Character mistake: Someone set up the chess board incorrectly. White should be on the right. (00:09:20)
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.
The Crackpots and These Women - S1-E5
Other mistake: When the President and his staff stop preparing for his upcoming press conference they decide to meet again "this afternoon" implying that it is still morning. In the very next scene Sam meets with the representative from United States Space Command he tells Sam that at 6:35 AM local time UFO's were detected over Hawaii. That's not possible. Hawaii is 6 hours behind Washington D.C. If it were noon in Washington, it would only be 6 AM in Hawaii, 35 minutes before the time the gentlemen mentioned.
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.
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.
Character mistake: While in the Situation Room Leo says twice "we need the calvary." According to Webster, calvary is a proper noun that refers to the hillside on which Jesus was crucified. Cavalry is a group of highly mobile army troops. Leo meant to say "cavalry" but mispronounced it. The subtitle is correct with the spelling "cavalry." Leo would definitely know better. (00:19:00)
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.