In Jake Gittes' final meeting with Jake Berman, an earthquake hits as they are talking inside the model subdivision home in Berman's housing development. There is a grandfather clock in the room. The earthquake cracks the glass cover on the face of the grandfather clock, and causes it to stop working. A few minutes later, when Jake Berman is in the house, about to light his final cigarette, the grandfather clock is ticking again and the crack in the glass cover on the clock face has disappeared.
A frightened Detective lieutenant Loach pisses his pants on the floor of the police room. In the subsequent shot, his pants are dry.
The door to Jake's office goes from closed to open while Lillian undresses.
Before the explosion, Jake Berman's car is seen at the top of the driveway. After the explosion, the car is at the bottom of the driveway.
In the courtroom scene (approx. 1:56 in), the DA's left lapel goes from folded under to out flat.
The movie begins with a voice over and a close-up of a Leica III camera apparently being used to secretly taking pictures of a tryst. Hands are seen focusing the lens, snapping the pictures and advancing the film. The Leica III uses a retractable lens for better storage in a camera case. The lens shown has not been drawn out from its compact position and therefore would not have been able to focus properly to take pictures.
Jake calls Tyrone from the Pacific coastline as the sun is setting. Outside Tyrone's office miles inland, the sun is shining brightly like midday.
On the golf course, Gittes tosses away his cigarette to drive the ball. When he is shown standing by to watch Berman tee off, he takes a drag on a cigarette that he not only did not have time to light, but did not have time to smoke it down to its current length. However, he simply picked up the cigarette he had just thrown down.
About 19' in, a muddy-footed person climbs through the window. He leaves wads of mud on the carpet, but didn't leave any on the window sill, despite putting one foot flat down on it.
Raw natural gas has no scent, which is why Jake lights a cigarette without concern. In order to detect the presence of gas, utilities companies add a small amount of mercaptan/methanethiol, which gives its distinctive smell.
When Jake Gittes is in his office, reviewing the wire recording of Jake Berman confronting his wife and her lover in the hotel room, he switches off the machine in mid-conversation, and immediately pulls the wire reel from the recording machine. However, since he's using a 1940s wire recorder, he would first need to rewind the reel before removing it from the machine.
Jake tells Ralph when they are standing in front of the laundry if he got dimes for phone calls. In 1948, the cost of a payphone was five cents. It didn't go to 10 cents until 1951.
Set in 1948, Jake strolls past an automatic teller machine.
Weinberger is wearing a modern pair of eyeglasses.
The stamp on the letter wasn't issued until 1949.
On the homes under construction in the B&B subdivision, the mottled texture of the sheathing indicates it to be Oriented Strand Board (OSB) and not plywood. OSB did not appear in construction until the Late 1970s and early 1980s.
When Gittes examines the newspaper clippings about the Chinatown killing, a headline refers to a "grizzly" death instead of grisly.