The Chief of Staff is often seen entering the oval office from his adjacent office. The only rooms directly next to the oval office are the secretary's office and the study. The Chief of Staff's office actually sits on the opposite side of the West Wing.
When Leo McGarry is on the phone with the New York Times complaining about the spelling of GADDAFI in the crossword puzzle, he says he has, in the past, recommended "a preemptive Exocet missile strike against his air force." The Exocet is an anti-ship missile, and the USA has never had any of them.
The light Mandy is pulled over for is yellow as she crosses the line not red.
In the opening scene, Toby states that they're flying on an "Eagle Series Lockheed L-1011 that came off the line 20 months ago". Production of the L-1011 stopped in 1985.
Sam speaks to Mallory for the first time, not knowing she is Leo's daughter. When he says the line, "And it turns out, I accidentally slept with a prostitute last night," his mouth does not match his words.
Sam says that the Cubans have left a "fishing village 30 miles south of Havana." That would be roughly in the middle of the island since Havana is on the northern coast of the island.
When Toby is irate about getting the names of the "damned
commandments right," he states that "Honor thy Father and Mother is the Third Commandment." It is the Fifth Commandment - although in Roman Catholicism and Lutheranism is it the Fourth Commandment.