Continuity mistake: When Rick is in the pool listening to Snoopy and the Red Baron, his radio is to his right. When the girl crashes through the window, the radio is to his left.
Other mistake: When he puts the 2nd can of dog in the bowl it's just a rerun of the 1st can being dropped in a bowl.
Factual error: Cliff is shown drinking a Coors Light in his trailer but Coors Light didn't come out until 1978 and the movie takes place in 1969.
Factual error: Most of the eyewear used has anti glare coating on the lenses, not used until the early 80's.
Deliberate mistake: After dropping Rick off at the set, we see Cliff driving his car back to the house to fix the antenna. View forward from inside the car, the rearview mirror is obviously missing. The next scene, outside with the car coming toward you, the rearview mirror magically reappears.
Other mistake: Over a car radio, KHJ's Robert W. Morgan is heard giving the weather forecast. The predicted high is "95 downtown, 105 in the valley." The scene takes place in the middle of winter, February 9, 1969.
Suggested correction: The daytime temperatures can reach that high in the winter.
The highest recorded temp for Feb 9 for Downtown LA is 89 set in 2016, and the highest February temperature ever there was 95 on Feb 20, 1995. "The valley" is too ambiguous to identify where it means. So while they "can", they don't, and any movie showing record-setting temps during winter, even if theoretically possible, would be considered wrong.
Factual error: In a scene taking place Sunday, February 9, 1969, KHJ's Robert W. Morgan is heard on the car radio. Morgan hosted a Monday-to-Friday morning show. He never worked on Sunday.
Factual error: The Cielo address is mentioned in the movie as being in Hollywood. It was actually in the Benedict Canyon section of Beverly Hills, several miles away from Hollywood.
Other mistake: When Cliff picks up Pussycat off the street, he mentions about picking her up on Burbank Blvd to take her to Chatsworth. This entire route would start and end in the San Fernando Valley, but when the journey begins, they enter the 101 freeway from Hollywood Blvd (nearly 10 miles away from anywhere near the route).
Factual error: In the beginning of the film, an aerial shot shows Cliff and Rick pulling out of a studio parking lot. The lines in the lot are yellow double lines between spaces. They didn't use that type of striping in parking lots in the 1960's. The parking lot striping was white with single stripes in between spaces.
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.
Factual error: When Cliff is driving home on the freeway, just before he takes the off-ramp, a numbered exit sign is visible. California did not adopt numbered exits until 2002.
Revealing mistake: As Cliff walks his dog down the street, and out of camera view, the hippies' car headlights can already be seen reflected in the back end panel of the parked car along the street (waiting for their cue). The car headlights are fixed, as the car stands still "parked" for several moments before pulling into frame when Cliff exits stage right.
