Continuity mistake: When Quicksilver duct tapes the guard in the elevator, the tape changes when Quicksilver and Magneto come back. For example, when they get back, the tape on the chin is now tucked under tape strips and there are more spaces seen.
Continuity mistake: Charles has just denied Logan's request for his help and is now in his bedroom. There's a photo of Raven on the right side of his bed with an ashtray slightly behind it. A couple of shots later, the ashtray is gone and the photo has moved closer to the bedside table's edge. (00:33:50)
Continuity mistake: Logan has just woken up in the past. In the first shot of him, the blanket is nowhere to be seen. In the next shot, the blanket now covers his stomach. (00:17:40)
Continuity mistake: Blink's boots change between three styles throughout the whole movie. They change between combat boots with low heels, combat boots with very high heels, and combat boots with medium-height wedges, depending on how much she is moving around in the particular shot.
Chosen answer: Government agents were previously aware of mutants - they are probably the same ones that imprisoned Magneto, and his attempt to prevent JFK's assassination was most likely covered up due to the revelation that Kennedy was a mutant. Magneto was already in prison by the time Trask pitched his Sentinel idea to the government, which is probably why the program wasn't instituted.
Phaneron ★