Character mistake: At the beginning they refer to the G8. Russia was removed from the group in 2014, making it the G7. (00:07:20)
Character mistake: After Wade is going over the second clue in his mind and trying to figure out what part of Halliday's past is he trying to escape from, he looks over the wall of article clippings and notes he has hung up. When the camera stops on Karen Underwood's obituary, there is a hand written note beside it listing movies set in New York, with the sentence "Set in New York" underlined. This apparently him looking for clues in films set there for the race challenge that is in Manhattan. However, one of the films he has written on that list is Mad Max, which takes place in Australia, not New York. (00:35:00)
Character mistake: Thor calls Nidavellir "Nivadellir" the first two times he mentions it.
Character mistake: When George throws one of the soldiers through the cockpit door of the plane, you get a brief glimpse at the pilot and co-pilot, both of which are wearing a Bose headphone/mic set. However the co-pilot has his one backwards, with the mic bent from the right side when it's meant to be on the left. (00:44:50)
Character mistake: Marion tells Robin "he chose you for a reason", despite not previously knowing that Robin was The Hood. So she has no reason to know that John chose Robin.