Continuity mistake: When Walter finds out about the Horsemen's plan to expose him on New Years Eve, Walter tells a bodyguard to get his father. The bodyguard begins to walk past Walter, but in the next shot, the bodyguard is suddenly at the other end of the room. (01:27:05)
Continuity mistake: When Walter and Tressler arrive in London, Walter gets into a car and begins to close the door. Chase is behind the car walking up to it, but when the car drives off in the next shot, he is suddenly standing beside the car, standing completely still. (01:28:45)
Continuity mistake: When Jack is performing in London, there is a woman directly in front of him, recording him on her phone. In one shot, she has her left hand across the left side of the phone and is holding it, but in the next shot, she is only holding the left side with only two fingers. (01:29:20)
Continuity mistake: When Daniel is performing in London, there is a wide angle shown in the scene, with Daniel under blue lighting. In all other shots in the scene, he is under white stage light. (01:34:10)
Continuity mistake: When Daniel reveals the case containing the card to Walter, his fingers are all bent and spread apart. When the shot cuts, his fingers are straight and close together. (01:43:25)
Continuity mistake: When Walter removes the card from the case after Daniel gives it to him, there is a close-up of the card in his hand. His hand is raised so that the palm of his hand is facing towards him. But in the next shot, his hand has turned around with the dorsal side of his hand facing towards him. (01:43:30)
Continuity mistake: After thinking they have thrown the Horsemen off the plane, Tressler peels off the label to the bottle that he and Walter are drinking from and finds the tarot card on it. He is holding the bottle by the bottom when he peels the label, but when he hands the bottle to Walter in the next shot, he is holding the bottle by the top. (01:46:40)
Continuity mistake: When Dylan shows Natalie the drive containing all of Walter and Tressler's dealings, in the shot focusing on Natalie, he can be seen closing the fingers in his left hand into a fist. When the shot cuts to focus on Dylan, the fingers in his left hand are not closed into a fist. (01:52:55)
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 Dylan comes across a picture of his father, in the shot focusing on the picture, he places his hand on the top left-hand corner of the picture frame. When the shot cuts to focus on Dylan, his hand is no longer touching the top left-hand corner of the picture frame. (01:55:13)
Continuity mistake: At the Royal Greenwich Observatory, when Dylan picks up the picture of his father and Thaddeus, he grabs the picture holding the bottom of the left hand side, but in the next shot, he is suddenly holding the picture much further up along the side. (01:55:25)
Continuity mistake: When Thaddeus is speaking to Dylan at the observatory, in the shot where Thaddeus says "You had let go of your thirty vendetta against me, for your Horsemen," Dylan is shown standing upright. In the next shot, his head is tilted to the left. (01:56:50)
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: At the launch party, Dylan is holding a playing card with 'The Fool' written on it. Dylan turns the card around whilst holding the card on the right hand side. From a different shot, he is holding the left hand side.
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