Factual error: Sharon Tate walks past a theater sign that shows the film Pendulum is playing. This movie is set in February of 1969, but that movie did not come out in the US until March of 1969.
Continuity mistake: During his conversation with the director, while discussing his costuming, Dalton's hair changes from messy and curled to gelled up and straight.
Other mistake: Cliff's dog is referred to as female but when it jumps up at a door towards the end of the film, it is male.
Factual error: Twice in the movie a Jumbo Jet (a Boeing 747) from Pan Am appears. The movie is set in 1969, when that plane had its maiden journey, but it wasn't flown commercially until 1970.
Continuity mistake: When Rick Dalton is talking to Jim Stacy, Jim Stacy's hat reappears on his head. (01:02:42)
Suggested correction: The cut is intentional, and meant to show passage of time.
Continuity mistake: ***SPOILER ALERT*** Towards the end of the film, when one of the Manson Family members falls into the pool, we see the water turn red with blood. When Dalton comes back with the flamethrower, the water is clear.
Revealing mistake: When Cliff Booth is driving Rick's Cadillac, in some angles the speedometer is showing 0 (zero) as the car is driven down the boulevard.
Factual error: As someone already noted, the Boeing 747 didn't enter commercial service until 1970. In addition, the Pan Am 747 type shown flying the characters back to the U.S. never existed. It has the extended upper deck common to the 747-300 and -400 series (introduced in the 1980's) but with only three windows (common to some -100 and -200 types). Also it has higher bypass engines which came later.
Continuity mistake: When crew members are watching the Bruce Lee fight, some are sitting comfortably and enjoying the fight, then right before Bruce gets tossed into the car, suddenly everyone is gone.
Factual error: Roman Polanski and Sharon Tate are attending a party at the Playboy Mansion in 1969. In reality, Hugh Hefner didn't purchase the mansion until 1971, and didn't start living there until 1974, which is when the house's reputation for lavish parties started.
Factual error: In the parking lot near the start, there is a blue VW Super Beetle with a curved windshield. The curved windshield debuted on the Super Beetle in 1973. This film is set in 1969. (00:14:58)
Continuity mistake: When Rick Dalton walks out of the saloon eating a chicken wing, he throws it into the street, where it moves around a couple of times from various takes.
Factual error: In the part where Sharon Tate goes to the theater to see her own movie, while showing the box office, you can see a modern dome security camera in the box office/ticket taking booth.
Continuity mistake: When Cliff is talking to the hippies about going to see George, the house is on his left side. We can see him from the hippie girl's point of view that is looking from George's house. When he turns and points to George's house, it's on his right hand.
Factual error: Pitt rides a triumph motorcycle which has a disk brake fitted to the front wheel. Disk brakes were not released on the market, for any motorcycle manufacturer until 1973. This film is set in 1969. The motorcycle would have been fitted with a drum front brake.
Factual error: A Starbucks sign is in the background when Sharon Tate is talking to the girl at the front of the movie theater; this scene takes place in February 1969, and Starbucks did not exist at all until 1971 and had no locations in Southern California until the 1990s.
Other mistake: When Cliff fights Bruce Lee the doors are already dented before Bruce gets tossed into them.
Character mistake: In the Western scenes, when the characters are wearing spurs, they have the spur straps buckled on the wrong side (inside) of the foot. Spur strap buckles are supposed to be on the outside, not the inside, of the foot. Since it's wrong in every scene, it might be a comment on the TV show itself having low attention to detail.
Continuity mistake: When Cliff is talking to George who says he wants to sleep to not bother Squeaky, George has both hands over his tummy, fingers crossed. A shot later his left arm is suddenly by his side.
Visible crew/equipment: When Rick returns to his caravan after he made a bad impression on the set, as he blames himself for not be able to remember the lines and saying: "You seemed like a f****ng baboon" a shadow of someone moving appears for an instant on the board of the table in front of him on left side of the screen.
