Anachronisms: When Ali starts to run in the streets of Kinshasa, we see a kid with a modern-style microscooter.
Continuity: When Cassius Clay is introduced to Nation of Islam founder, Elijah Mohammed, to be given the new name - Mohammed Ali - the Revox tape recorder on the table disappears between shots.
Anachronisms: Some of the Nikon cameras used by the press are modern, not 1970s, models.
Continuity: Ali sits down twice when Malcolm visits him in his hotel room.
Anachronisms: When Ali and Liston are getting weighed, one of the people takes a photo using a Canon EOS, a camera not made in the '70s
Anachronisms: When Ali is jogging in the very first scene, there's an '87 Taurus in the background, and a '90s vintage car in the carport.
Anachronisms: In scenes from the 1960s, Howard Cosell is depicted wearing a hairpiece. Cosell didn't start wearing a hairpiece until the early '70s, prior to which he slicked back his receding hairline.
Factual errors: Chauncey Eskridge was not at the Lorraine Motel in Memphis standing directly under Martin Luther King Jr. at the moment of King's April 4, 1968 assassination (the director knew this).
Anachronisms: In the fight with Sonny Liston, the ring had three ropes not four as depicted in the film. Boxing rings didn't have four ropes until the mid-1970s.
Continuity: When the FBI is setting up the wiretaps, the cigarette and ashes jump around in the ashtray between shots.
Anachronisms: Ali exchanges winks with a ring card girl in the George Foreman fight. According to boxing historian Bert Sugar, ring cards girls were not in existence until the late 1970s at Caesar's Palace.
Anachronisms: There's a scene where Ali is standing on a city street with a Sears department store in the background. The logo is current as opposed to that used in the '60s and '70s.
Factual errors: In the last fight of the film, Ali always sits down between each round. In reality, he never sat down in this fight.
Continuity: In the scene where Ali, Bingham, and Belinda are watch the Frazier-Ellis fight, the fight is in black and white in one shot and color in a later shot when Frazier wins.
Incorrectly regarded as goofs: In the early '60s section of the film Clay refers to a member of the Beatles ('John Lennon' we presume) as "the one with the glasses". Lennon seldom wore his glasses in public (though there are a few studio photos), and was certainly not famous for them, until 1967. It is possible however that Lennon would have been wearing his thick-rimmed black glasses when the Beatles met Clay during their first visit to the U.S. in February 1964, then removed them for the publicity shots taken during that visit.
Factual errors: The argument Ali and his wife Sonji have over Ali's seeing Veronica Porche did not happen before the Ali/Foreman fight, but instead happened before the 3rd Ali/Frazier fight, "The Thrilla in in Manila", in 1975.
Factual errors: The officer at the induction center wears the belt of an Army officer (black), indicating that he is an Army captain, yet he wears his rank like a Naval or Coast Guard lieutenant (with the bars' center line bisecting the collar angle, and lacking branch insignia on his left collar).