Anachronisms: Set in 1948, Jake strolls past an automatic teller machine.
Continuity: A frightened Det. Lt. Loach relieves himself on the floor of the police room with his trousers on. In all subsequent shots his trousers are dry.
Anachronisms: The stamp on the letter wasn't issued until 1949.
Anachronisms: 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.
Revealing mistakes: "For Redheads Only" is backwards on the door in the salon when Gittes enters, revealing the use of a mirror image.
Continuity: On the gold course Gittes tosses away his cigarette to drive he 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.