In the interview scene with James Corden, Jack's fly is initially open. When it cuts back to the interview moments later it is closed.
After Jack's accident, he shows off his missing teeth several times. It's clear that he's lost the two large teeth just to the right of center. All the teeth to the left of center are still there.
After a dentist repairs the damage, his two new teeth (clearly different from the others) are directly in the middle: one to the left of center and one to the right of center. They are one position different from the ones he lost.
After a dentist repairs the damage, his two new teeth (clearly different from the others) are directly in the middle: one to the left of center and one to the right of center. They are one position different from the ones he lost.
After Ellie drops Jack off at night Jack is standing alone on the road and it looks like he starts realizing what is happening or what has happened. He runs to his room and starts searching in computer and finally finds out that the Beatles doesn't exist and never existed. Taken aback and perplexed he stands up. Then he is shown in a quick sequence through different camera angles. In this sequence there is a very short clip in which he is still visible sitting in front of the computer screen.
As the sudden blackout ends, the lights come on in Moscow with busy traffic flowing freely - when moments before it would've stopped due to many car crashes.
When Ellie comes to find him in Liverpool he says she was "370 miles away". If they are British he would have used kilometers.
When the blackout occurs, there are shots of various places across the globe simultaneously descending into darkness, yet half of the globe would have been in daylight - except the daylight half is mostly Pacific Ocean with the USA after sunset in the west, night-time Eurasia in the middle, and Japan before dawn in the east.
The first time Jack googles The Beatles in his room, there is a Killers poster on the wall behind him. The Killers were formed after their lead singer Brandon Flowers was inspired by an Oasis concert he had attended. Later in the movie, it is established that Oasis had also been wiped from existence as a result of the blackout. Therefore, The Killers would likely not exist as well because Brandon Flowers would not have attended an Oasis concert. Response: There is no way to know if The Killers would have been created if Oasis did not exist. In the alternate reality that movie creates, Brandon Flowers would have been inspired to form a band while watching a different concert.
The gig for the hotel's re-opening seems remarkably poorly attended despite months of being trailed as the single most important music event EVER.
Near the end of the movie when Debra begins her race to the stage, she comes through a doorway and is clearly heard saying "Where's the stage?" while her lips are not moving.
When Ellie and Jack have their conversation in the sub shop in the train station Rockie barges in to tell them he was supposed to FaceTime with Debra and some executives while at dinner. The only problems with that is that they mention that it is a little after 11 am GMT which would be 3 am PST.
During a crowd shot at Wembley Stadium, London, a grandstand sign saying "Principality Stadium" can be seen. This is the sponsored name of the Millennium Stadium in Cardiff, Wales.
The two other characters who remember The Beatles bring Jack a yellow submarine, which appears to be a mass-produced toy, that wouldn't have existed without The Beatles' music.
When Jack is given the guitar he takes it out of the case and starts playing it without first checking if it's tuned. No experienced musician would do that, especially when they don't know how long it's been in the case and when it was last tuned.
When confronting Jack about the origin of his songs Liz say that "You can't write songs about places you've never visited" and mentions that Jack went to see Eleanor Rigby's grave. In fact, the song was not inspired by the grave. Paul McCartney said that he got the name "Eleanor" from the actress Eleanor Bron, who appeared in The Beatles film Help! (1965). "Rigby" came to him when he was in Bristol, England, and spotted a store: Rigby and Evens Ltd Wine and Spirit Shippers. He liked the name "Eleanor Rigby" because it sounded natural and matched the rhythm he wrote.