Continuity mistake: The nice guys take Amelia to March's house and put her on the bed. She's lying on the bed, left arm stretched, green pillow shifted definitely towards the right. When she comes to, her arm is bent and the pillow is centered. (01:12:45)
Factual error: The poster of Paul Simonon of The Clash in Holly's bedroom was neither captured nor made famous on the sleeve of 'London Calling' until 1979; the Nice Guys is set in 1977. (01:13:00)
Factual error: During the scene with Amelia in Holly's bedroom, on the wall you can see the iconic photo on the cover of the "London Calling" album by The Clash. It's a photo with the bassist smashing the guitar onstage at the Palladium September 20, 1979, almost two years after the movie supposedly takes place. But there's also a Blondie poster on the right of the bed which, while based in fact on a shot from 1976, is a modern cheap styling in pink leopard print widely, marketed on the internet today but that is not appropriate to the time period. (01:14:00)
Continuity mistake: When Haley asks "Why not go straight to the police", Amelia has just a bit of her hair in front of her left shoulder, a greater portion of it in the next shot. (01:14:55)
Continuity mistake: There's a brief cut to Ryan Gosling saying the line "Okay, so it's like Jack the Ripper and then your mom, basically." Amelie doesn't move, but her hair changes position completely. (01:16:05)
Continuity mistake: Jessica is on the phone and asks the person on the line "Richard something? Yeah." Holly in the background just puts her hand one one of the nearest cards, but at the cut she's moving her hand back from the top of one of her solitaire lines. (01:22:00)
Continuity mistake: John Boy draws the knife and makes his generous 'offer'. Cuts back to the Nice Guys who are driving fast; the Mercedes, as dirty as it is, is still perfectly intact with both sets of headlights working and the hood ornament. The front section was damaged when March fell asleep at the wheel earlier, and the car is again damaged when they pull over in the driveway. (01:24:10)
Continuity mistake: After the encounter with John Boy, March asks Perry a question. He says "They havent', and they are not going to." The sentence spans across two shots, with a visible gap in continuity in the way Russell Crowe puts his sunglasses on. (01:28:25)
Continuity mistake: Mrs. Glenn drops by to chat about the case; during the scene, her large square necklace is under or above her dress, randomly. (01:30:15)
Continuity mistake: When Mrs. Glenn shouts at March for cussing, she points at him with her left hand. Next shot and she's pointing with the right. (01:31:10)
Continuity mistake: When March says "Tally! Oh my God, you look incredible", he opens his arms, which are still firmly down his sides in the next shot. (01:34:55)
Continuity mistake: Holly throws coffee on Tally, but her face and dress are clean a moment later. (01:37:30)
Revealing mistake: In the shootout on the roof, the CGI blood spurts are phony, their light does not match the scene. (01:41:00)
Continuity mistake: When the older guy falls back and tries to drag Holly with him, she wiggles free leaning towards him, but in the reverse shot she's rotating the other way. (01:41:05)
Continuity mistake: John Boy throws his jacket in the street, but in the brief shot where Jackson tackles him he's still wearing it. (01:44:55)
Continuity mistake: When at the end of the movie Kim Basinger sits with the Nice Guys (well, back-to-back with them, kinda), March is already wearing the sunglasses that he puts on when she says "Boys, boys." (01:47:15)
Continuity mistake: When the Nice Guys in the ending mention Lynda Carter, they are holding their smokes in entirely different ways between shot and reverse. (01:50:25)
Factual error: At the end they are drinking from a bottle of Captain Morgan's spiced rum. The movie is set in 1977, and Captain Morgan wasn't introduced to the US until 1984. (01:50:55)
Factual error: The movie takes place in 1977. A boy tells his father he is playing PacMan, which came out in 1980. Then we see a cabinet of Ms. Pacman, which came out in 1982.
Factual error: In the party scene Earth, Wind and Fire's song September is performed. The song was released November 18, 1978. The movie is set in 1977.
