Continuity mistake: When Libby goes to the BMW dealer, the dealer says the address is 20 Oriole Terrace. When Libby is driving down Oriole Terrace, she passes a house with four digits in the address.
Continuity mistake: In the scene where Ashley Judd leaves prison and first meets Tommy Lee Jones, she brings a box into his office full of her belongings. After he has checked through it he looks at the picture of Judd's son. When he throws it back into the box, it makes a noise as if it has hit the bottom of an empty box. In the next shot Judd picks up the box which now seems to be full with all of her belongings again, even though he hadn't put anything else back into the box.
Continuity mistake: In the opening scene where Libby is talking to Maddy. When the camera is in front of them, they're facing each other. But when the camera shows them from behind, they are sitting beside each other.
Continuity mistake: When Libby asks Angie to adopt Maddy, in one minute her legs are up on the chair, and in the next, they're hanging down again.
Continuity mistake: When Jonathon puts Libby in the casket and she realizes where she is, she grabs her backpack to get the gun. From shot to shot the lighter she is holding goes from her left hand to her right hand to her left hand, etc.
Continuity mistake: In the last scene when she meets her son, he has his head forward over her shoulder, then he turns his head to the side on her shoulder. But when the camera goes to show the front, his head is again straight over her shoulder, not sideways. (01:40:00)
Answer: Because there were exceptional and extenuating circumstances and, technically, Libby was never guilty of the crime she was convicted of and had to resort to extreme measures to prove her innocence. She may have had a gun, but it could never be proved that she held Nick at gunpoint, only that she shot him in self defense. Also, it's a movie, which often are unrealistic regarding details like that.
raywest ★