Other mistake: The opening credits show a bit of Ava's rather extravagant biography. She is involved in a DUI accident that kills two people; the news article says that it happened "early Thursday morning." What follows is a police photo labeled 06/27/95, a Saturday. Then we see the police report; not only the incident time is 10:30 PM, but the date is March 15 1999, which was a Monday. It is not separated incidents, since the police photo is then shown again, next to the "Thursday" article (and the fact described in the article is life-changing). (00:08:10)
Other mistake: Ava disposes of her target and reports her Executive code (74598CG). Then she gets as reply from her handler "Management code 840227." Later we see Duke's management code, and it's different (96729CF), which is also the one she types on the plane.