After Sam gives Will Bailey his tie, the shot of Sam walking away is very clearly not the actor, Rob Lowe. Hair is shorter, body shape is wrong.
When Senior Staffers are waiting outside the Oval Office in the beginning sequence, C.J. Cregg is shown with a clipboard that only has a $10 bill on the outside; however, when the camera pans back around to her and Toby points out the $10 bill, there is a piece of white paper underneath the bill which wasn't there originally.
When Will swallows a pill he starts off holding his mug by the handle. After a cut he holds it by the body.
The California 47th Congressional District does not include Newport Beach, CA. It is comprised of Cypress, Los Alamitos, Rossmoor, Stanton, and parts of Garden Grove and Westminster (all in Orange County), as well as Long Beach, San Clemente and Santa Catalina Islands (Los Angeles County). Newport Beach is in Orange County but it belongs to the California 48th Congressional District.
There is no San Antonio class LPD named USS Austin. The San Antonio class amphibious transport dock replaces the older Austin class, with its lead ship USS Austin (LPD-4) serving until 2006, when the USS San Antonio (LPD-17) was commissioned.
Sam Seaborn tells Will Bailey that he "grew up two blocks from here" (in the California 47th). Yet, getting out of his rental car, he folded up a street map. Later on, he asked Will for clarification of how to get onto the 405, something an area native would already know.
While answering reporters' questions on why the Horton Wilde campaign continues even though the candidate has died, Will Bailey gives a short list of reasons including their opponent, Chuck Webb, having "...once challenged another Congressman to a fistfight on the (House) floor, over an amendment to make stalkers submit to background checks before buying AR-15s, AK-57s..." However, there is no such weapon as an AK-57. The most commonly known assault rifle of America's Cold War adversaries - and many of its current enemies - is actually the AK-47.