The song that Billy Beane's daughter plays on guitar and sings is "The Show" by Lenka. However, this song was not released until 2008. The films events takes place in 2002.
In an aerial shot of the Oakland stadium the Oracle Arena can be seen but the film takes place in 2002 when it was still known as the Oakland Arena. It was not renamed to Oracle Arena until 2007.
Peter Brand (Jonah Hill) wears an all-green Oakland A's cap with yellow logo and a black-colored under-bill. However the black-colored under-bill was not a feature for New Era caps until 2007, when they debuted 100% performance polyester caps with the black-colored under-bill to reduce glare.
Many of the televisions in the film are large flat panel HDTVs which were not introduced until several years after the film takes place.
When Billy visits Fenway Park, the Red Sox championship banners from 2004 and 2007 are visible, though this takes place in 2002. Also, the seats above the "Green Monster" are visible, the seats were not completed until the beginning of the 2003 season.
Continuity In 2001, when Scott Hatteberg is first shown on screen, his feet are up on a coffee table, clearly showing the Nike+ logo on the sole of his shoe. Nike+ was not introduced until 2006.
When Billy is teaching Peter how to fire someone, the paper "spit" cup and the coffee cup in front of Billy keeps moving further behind the telephone on the desk.
When Peter is flashing through all the players in his database, one player passing by is seen wearing a Toronto Blue Jays hat. The logo on the hat was not introduced until 2004.
Casey specifically asks for a small spoon (i.e. tea-spoon) to eat her dessert with, but is seen using a large spoon (table-spoon).
Although the film depicts the signing of Jeremy Giambi by the A's in 2002, he was actually already with the team for 2 years and was known for not sliding into home on the infamous Derek Jeter "flip" play during the 2001 Division Series.
In one of the film's flashbacks, Beane is shown as a New York Met playing at Dodger Stadium against the Los Angeles Dodgers. As a player, Beane never played a game at Dodger Stadium, nor did he ever play a game against the Dodgers.
Incorrectly regarded as goofs The movie takes place right after the 9/11 attacks, when most non-passengers would not be allowed to say goodbye to passengers at the gate, inside airport security, as Billy Beane does. However, Beane is allowed to because his daughter is flying as an unaccompanied minor; as her guardian, he is allowed to escort her through security to the gate even though he is not flying.
Spoilers The goof below may give away important plot points.
Factual errors Game 5 of the 2002 ALDS between the Oakland A's and the Minnesota Twins is filmed as a night game. The actual game 5 on October 6, 2002, was a Sunday day game, and started at 1:00 Pacific Time.