Continuity mistake: In the opening scenes, the police officer carries a shotgun to his vehicle. When he gets into the car, he's got a flashlight and a nightstick.
Continuity mistake: When Earl's wife returns home and gives Earl the fluid tranquiliser, she puts the white medicine bag on the side table near the bed. Later on when she is in the car, she takes the bag out of the pocket of her coat, but it wasn't in her coat.
Continuity mistake: The length of Claudia's hair changes during what seems to be a period of time shorter than a day. A similar thing happens with the colour of the bartender's lover's hair - it changes from almost blonde to dark brunette.
Answer: It's much debated the exact meaning, but it's kind of a reference saying that seemingly impossible things do happen. As we see later in the film, people stuck in similarly impossible situations might just have a chance of getting out of them.
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