Character mistake: Dylan is showing Agent Cowan and the FBI director the pictures of the pigeons and Dylan and Cowan start arguing, while the FBI director continues to look at the evidence on the Four Horsemen. Whilst looking there is an article reading "FBI Investigation Stalls." On the first column of the article, it is mentioned that all four members of the Four Horsemen, J. Daniel Atlas, Henley Reeves, Merritt McKinney and Jack Wilder, all disappeared into thin air at the final magic show, and gave the audience fake dollar bills. By the time of the final magic show, Jack had faked his death and was presumed dead, so only three members of the Horsemen were present, not four. (00:08:55)
Continuity mistake: When Daniel is communicating with "The Eye", he walks over to a well and places his phone down around the rim of it. The phone is beside the edge of one of the blocks covering the rim, to its left. When Walter is explaining to Daniel later on in the movie that he was the voice, the scene cuts to a flashback, and Daniel is now shown placing the phone beside the right hand side of the edge of the block. (00:06:05 - 01:10:55)
Continuity mistake: In the first Now You See Me, Dylan said before his father got into the safe that was dropped into the river he gave Dylan his watch to hold so he could count the seconds until he escaped, but in Now You See Me 2 there's a flashback that showed what happened before his father got into the safe and he does not give him his watch. Instead it shows Dylan and his father both with a watch and synchronizing them together.
Continuity mistake: When the Horsemen are onstage at the OCTA party, Dylan opens his iPad and notices a tarot card on it. In the close-up shot, when the tarot card is first shown, it can be seen slightly passing over the edges of the iPad, but in the shot previously, Dylan is opening the iPad, but the tarot card is nowhere in sight. It would have been visible even from the camera angle that was shown. (00:22:45)
Continuity mistake: When Merritt is explaining to Daniel, Jack and Lula that they are in China, he starts saying "I think where we are right now, they don't refer to it as Chinese food." In this shot, he is standing beside Lula, maybe a few inches ahead of her, but in the next shot, Merritt is suddenly a couple more feet ahead of her. (00:27:20)
Continuity mistake: When Owen Case is being introduced at the OCTA launch, Merritt and Lula are backstage and Merritt says "Nice work, lady" whilst putting his hat on. In the next shot, his hands are suddenly by his side. (00:20:30)
Continuity mistake: When Walter Mabry is explaining how the Horsemen ended up in Macau he walks over to sit on the couch to show the slideshow of the plane trip. As he walks over, Atlas is not on the same couch as the other Horsemen, but when Walter goes to sit down he squeezes between all of the Horsemen with Atlas now on the end of the same couch as everyone else.
Continuity mistake: When Walter is explaining to Daniel he was the voice he heard earlier in the movie, he mentions that he put his phone on a by-wave syphon pad, the scene flashes back to when Daniel was communicating with the voice and it is discovered there was a device planted inside the well, shown behind a grid. When Daniel visited this place earlier on in the movie, the grid inside the well was visible, but there was no sight of the device inside the grid. (00:06:05 - 01:11:00)
Continuity mistake: When Agent Cowan is asking the FBI director what happened, she says that they are gone and tells the man beside to come with her. She and the man then start walking, with the FBI director walking a couple of feet ahead of the man. In the next shot, the man is still behind her, but suddenly slightly closer. (01:53:50)
Continuity mistake: When Daniel is trying to take the OCTA CCTV guard's ID pass, he takes a picture of him with a Polaroid camera so that he can stick it onto a tag to prove that he is from a mental hospital. When the picture prints out from the camera, all that is shown is shown is the image of the guard against a white background, instead of the wall seen behind him. Also, when Daniel takes the picture, the guard has his head turned to the right to face Daniel, but when the picture prints, the guard has his head positioned completely forwards. (00:17:40)
Continuity mistake: When Walter is explaining his relationship with Owen to the Horsemen, Merritt's position changes whenever the shot is on him. He is either sitting on the couch with his arm on the arm rest and leaning forward, sitting with his arm on the arm rest and has his back against the couch or sitting with his back against the couch with his hand in his lap. (00:37:45)
Continuity mistake: In the first movie, when Dylan and Alma first meet up with Thaddeus Bradley for lunch, he mentions that Lionel Shrike was a magician in the 1970s and one year later, attempted the safe in the river trick that killed him, but in the opening scene of this movie, it is shown that the safe in the river trick that killed Lionel Shrike took place in 1984. (00:00:35)
Continuity mistake: When Dylan is showing the FBI director and Cowan the photo of who may be Merritt McKinney, he is standing next to the director turned to the right, but in the next shot, the two are suddenly directly facing each other. (00:08:15)
Continuity mistake: When Dylan is showing the FBI director and Cowan the photos of the Horsemen, just as the FBI director asks what it all means, she is looking at Dylan, but in the next shot, she is suddenly looking at the photos. (00:08:50)
Continuity mistake: When Merritt fails to throw the card, Jack says "it's good to be positive despite having made zero progress in a year" whilst looking at Merritt. In the next shot, Jack's head is suddenly turned about 90°. (00:12:50)
Audio problem: When Dylan begins explaining the plan to infiltrate OCTA to the Horsemen, there is a wide shot where he says "OCTA's hosting the launch of the next-gen cell phone" but his lips don't move at the start of the line. (00:15:40)
Audio problem: At the OCTA launch, when Daniel calls security for the CCTV guard, the security guard finds the Evans Mental Facility wristband on his wrist, then the CCTV guard says "Hold on a second" but his mouth doesn't move. (00:18:10)
Continuity mistake: The banana that Jack takes from the woman at the metal detector when he is posing as a security guard at the OCTA launch is different to the one he plants in the CCTV guard's pocket a few minutes later. (00:16:25 - 00:18:30)
Continuity mistake: When Walter begins hijacking the Horsemen at the OCTA launch, Dylan says "let's go to the back", and the FBI director tells him to stay here. There is a bald FBI agent standing in front of him to the right, but in the next shot, the FBI agent is suddenly behind him. (00:24:15)
Continuity mistake: When the Horsemen land inside the baskets in the Chinese restaurant, in the shot focusing on Merritt, Daniel is seen beginning to stand up, but in the next shot, he is suddenly lying back in the basket. (00:26:10)
Answer: The only ones who knew the chip was fake were the Horsemen, no one else did. Walter did not know the chip was fake. The plan was to convince Walter that the chip was real so that they could lure him out of hiding with Walter attempting to kidnap and later kill them, and expose Walter to the public in doing so. They told the crowd after exposing Walter about the chip, because while it was a fake, they still had plans with it assuming it was real. If by "alert the FBI", you were referring to when Dylan gave the FBI director the evidence on Walter and Tressler, that was not the chip he gave to her, that was a hard drive containing all of Walter and Tressler's past dealings.
Casual Person