Continuity mistake: When Deckard asks K if he has a name, K lifts his glass an inch off the counter and tilts it towards him to look inside it. The shot cuts to a different angle where the glass is now lifted further off the table. (01:52:25)
Continuity mistake: When K is asking Deckard about Rachel, just after he asks what was she like, the shot cuts to Deckard where he has his glass tilted to the right. The shot cuts again where the glass is more tilted to the left. (01:53:05)
Continuity mistake: In the casino, when K and Joi hear an alarm going off, K lifts his hand up and switches off the emanator, but in the next shot, his hand is suddenly back in his lap and the emanator has disappeared from his hand. (01:57:40)
Continuity mistake: When K and Deckard realise that Wallace's thugs have reached them, K picks up a pair of binoculars and looks out to see. The binoculars have a strap extending from them at first, but from another angle, the strap is no longer visible. (01:58:05)
Continuity mistake: When Deckard heads for his car after he is found, he runs into a room with his dog, locking the door. He and the dog then run towards the car, with the dog running ahead of him, but in the next shot, the dog is suddenly behind him. (01:58:35)
Continuity mistake: In the shot of K and Deckard being blasted back by the missile, they are right next to each other when they are about to land. In the next shot, they are suddenly meters apart. The dog also reappears in between them when they land. (01:58:45)
Other mistake: It is established in the movie that whenever Joi is switched on through the emanator, or when she tries to communicate with K when switched off, a chorus line from the song Peter and the Wolf will play. This is shown at numerous points: when K first activates the emanator, when K is talking with Luv at Wallace Corporation, when K is talking with the hooker, when K switches her on when he is analysing the DNA, when she is reset after the car is shot down and when she switches herself on to tell the hooker to leave the apartment. However, when Luv is beating up K, Joi switches herself on to tell Luv to stop, but the chorus line from Peter and the Wolf is not heard, despite being heard every other time in the movie. (02:00:30)
Continuity mistake: When Luv attacks K after taking Deckard, Joi switches the emanator on to get her to stop. The emanator has a light around the button whenever it is switched on. Luv walks up to the emanator and the light on the button is suddenly not on. Luv then raises her foot to stomp on it and the light is switched back on again. (02:00:35)
Continuity mistake: When the three cars are driving through the city back to Wallace Corporation with Deckard, there is a shot shown from behind. In the shot, the car on the left is flying highest, the car on the right is flying lowest, and the car behind is flying in between the two. The shot then cuts to a wide shot, where the car on the right is now higher up than the car in the middle. (02:02:55)
Continuity mistake: When Mariette is with K in the replicant hideout just after he wakes up, there is a moment where Mariette is shown placing her hand on the side of K's face. It then cuts to a shot focusing on Mariette, where her hand has moved down to the side of his neck. (02:04:00)
Continuity mistake: When K looks over to notice Freysa and the other replicants approaching him, Mariette has her hand near K's neck with her finger against his face. The shot then cuts to angle behind K where her hand is now around his neck. (02:04:05)
Continuity mistake: In the replicant hideout, when Freysa is approaching K, the shot where Mariette tells K he can trust them, she has her hand around the back of his neck, but when the shot cuts to a different angle, her hand is suddenly near the front of his neck and moving away. (02:04:15)
Continuity mistake: When Freysa is speaking with K, she raises his gun so that it is pointed at her. Just after she says "Dying for the right cause is the most human thing we can do", when the shot is on K, he lowers the gun slightly and it goes out of frame. It then cuts to a shot focusing on Freysa, where the position of the gun remains the same and doesn't change. The shot then cuts back to K at the same angle, where the gun is now visible at the the bottom of the frame, even though the gun didn't change position. (02:06:25)
Deliberate mistake: When Deckard wakes up in Wallace Corporation, there is a wide shot of the platform he is on. All four corners of the platform are empty in the wide shot. Deckard then looks at Wallace's visual aids as they float away, and then realises Wallace is standing in the corner directly facing where he is sitting, speaking to him. This corner was empty in the wide shot, with no sign of Wallace. Wallace could not have entered in between shots because Deckard would have seen him approaching or at the very least, heard his footsteps. This was likely done intentionally as to not give Wallace's reveal away too early. (02:08:55)
Continuity mistake: When Deckard awakens in Wallace's office, after Wallace's visual aids leave and Deckard hears Wallace, he is lying back in the seat with his arms in the armrests. The shot cuts to an angle behind Deckard, where he is now suddenly hunched forwards. (02:09:15)
Continuity mistake: When Wallace says to Deckard "It was very clever to keep yourself empty of information, and all it cost you was everything. But you can still help me", the light above them begins to shine on Deckard, and his shoulder is covered in light. The shot cuts to a shot in front of Deckard, where his shoulder is suddenly much more shadowed, before being lit a second time. (02:13:20)
Continuity mistake: When Wallace tells Deckard "Pain reminds you the joy you felt was real", Deckard rests against the back of the chair he is sitting in. The light above them moves away from Deckard, leaving him shadowed, but when the shot cuts to an angle behind Deckard, the front of his face is suddenly covered in light. (02:14:15)
Continuity mistake: When Harrison Ford meets Rachael again, he says she is not accurate because "she had green eyes." But when Rachael is being interviewed for the first time in the original, her eye is displayed on the monitor. The eye is not green. (02:16:05)
Continuity mistake: When the giant Joi walks over to K, the wide shot shows her stopping in front of the platform he is standing on, directly facing K's direction. The shot cuts to her kneeling down, and she has suddenly turned 90° to the left. (02:17:00)
Continuity mistake: Whilst the giant Joi is chatting up K, there are streaks of wet blood shown going down his neck due to his injuries getting rained on. These wet blood streaks continue to grow for the next thirty seconds. When he takes off the bandage over his nose, the wet blood streaks on his neck have disappeared. (02:17:12 - 02:17:55)
Answer: Think of any manufacturing process. Samples of new products are frequently created and then immediately destroyed. Also, the new replicant would require processing, training, etc. It was simpler for him to just dispose of the test.