Audio problem: At the beginning of the movie there is a woman riding a motorcycle. It seems to be an adventure bike, but the sound is from a Harley Davidson type of a bike.
Character mistake: The protagonist is a flippant murderer who was a genius honor student in college and undoubtedly rehearsed the lines she uses for her victims. Sadly, when she says "You know, Croesus once said 'Count no man happy until the end is known'" she is not doing a good job; it's not Croesus uttering that line, but (according to Herodotus) Solon, TO King Croesus. (00:03:00)
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)
Continuity mistake: Final hotel fight scene. She starts off wearing shoes, and then they disappear and reappear.