Other mistake: Bryant mentions that 'six skin jobs' escaped and that one got fried trying to get into the Tyrell building. Four of them die in the movie, so what happened to the last one? [In the "Director's Cut" and "Final Cut" versions the math has been fixed. Bryant now says that two of the replicants got fried, not one.]
Other mistake: When Deckard and Bryant are viewing the interview tape showing Leon's interview at the Tyrell Corp they are shown Leon's replicant statistics. The tape shows Leon's model number: N6MAC41717. This designates Leon as a: Nexus 6, Male, Physical Level: A, Mental Level: B, and an incept date of: April 17, 2017. The incept date shown under his model number is: 10 April, 2017. As Deckard and Bryant continue to watch the tape they see the other replicants: Roy, Zhora and Pris with their individual statistics showing a matching model number to their incept dates.
Continuity mistake: The Asian chef calls Deckard over to order his food once a seat becomes available. There is a guy in a yellow shirt sitting next to the open seat. A blue bottle of some sorts is right next to this guy's arm. When Deckard comes over, the blue bottle has vanished. It appears again once Deckard sits down to his left by the yellow guy's arm. And then after the chef gives Deckard his food, the blue bottle is suddenly on Deckard's right.
Continuity mistake: While waiting in the rain for his food, the chef across the street calls Deckard to come over. Deckard folds his newspaper and puts it over his head to shield himself from the rain. The paper is folded messily and the crease side is in his hand. When he gets to the other side of the street, the fold is suddenly much cleaner and neat, and the crease side is on the outside, no longer in his hand.
Continuity mistake: The scene where Roy saves Deckard's life and then dies takes place on a very dark and rainy night. After Roy says his final line, "time to die", the white dove in his hand gets loose and flies away. The next shot shows the bird flying in a totally clear cloudless sky, with lighting that suggests that it is becoming morning. The next shot is of Deckard, back in the heavy rain and total darkness.
Revealing mistake: As Zhora is crashing through the last window, after being shot by Deckard, there are dark pads visible around her lower arms. In few shots before, these are visible whilst crashing, but not whilst she is running or falling.(US theatricalcal version).
Continuity mistake: When Deckard makes a hardcopy of the picture on the screen, it doesn't match the screen picture. The screen shot is a profile of Zhora; the hardcopy is a frontal view.
Other mistake: The snake scale changes size and shape each time it's seen, it begins as a large hexagonal shape bigger than Deckard's finger tip when he first finds it, it's later seen as a very small triangular shape in the sample bag and it ends up as a guitar plectrum shaped object when he hands it to the street merchant for identification.
Continuity mistake: When Deckard is snooping about in Zhora's dressing room asking questions. We see her putting on high heel mid-calf boots (just under her shin pads). Watch the chase sequence soon after. Especially when she gets shot and is on the ground picking herself up, you can see she is wearing what looks like black trainers.
Revealing mistake: There are at least two rain related problems in the city exterior shots: it's noticeably misaligned when Rick and Gaff are outside Leon's apartment building (towards the right it falls straight down, yet towards the left it falls at an angle). The second is when Gaff encounters Rick and the now dead Baty on the hotel roof; despite previous shots showing no awning or any type of cover above said roof, Gaff is visibly dry and actually standing in front of the rainfall, only getting wet when he steps into the background.
Other mistake: When the woman puts the snake scale under the microscope she doesn't take it out of the bag. She turns on a monitor to view the image; the image when shown is on a different monitor (you can tell by the controls to the right of the image). The image is not a snake scale, it is a marijuana leaf from the Sharf book (his book is in the ending credits).
Continuity mistake: The dialogue between Holden and Leon in the beginning never matches the interrogation tapes during the films (excluding Deckard's recall a moment before he confronts Pris). Most notable are the time and speaking manner. It can be heard when Deckard and Bryant listen to the tape.
Continuity mistake: When we first see Deckard he is sitting down and reading a newspaper. After a little bit of time a seat becomes available at the restaurant across the way. The cook calls him over. Deckard then folds the newspaper once and places it over his head to shield himself from the rain. We see him run across the thoroughfare and off camera. It then cuts to him making his last couple steps to the waiting seat and the newspaper is now folded twice.
Continuity mistake: When Deckard shoots Zhora, she crashes down through a glass wall and her cape is rolled over her head; in the next shot, In which she's crawling on the floor, her cape is straight behind her back.
Continuity mistake: Just after Rachel asks Deckard if he ever took the VK test himself, she walks in after no response and sees that he has fallen asleep. Before the camera shows him sleeping, she is shown walking into the room, clutching a drinking glass with both hands in front of her. The camera switches to Deckard for a couple seconds, then back to Rachel. She is standing in the same spot, with no immediate area to set the glass down at, but her pose has completely changes where she has one hand on one hip, and the other arm limp at her side. At which point she then reaches forward with her left hand to grab a picture off the piano, and the drinking glass has vanished.