Continuity mistake: When Bitsey first meets David she sits down and is seen reaching down into her briefcase for her notepad. The camera angle changes and she is now seen sitting straight up. Camera angle changes again and she is seen reaching down again. (00:18:25)
Continuity mistake: During the scene where they show David teaching, he asks the class if they fantasize about winning the Pulitzer Prize and you can see him walking with his arms outstretched. The camera angle changes and his arms are now at his side. (00:20:28)
Continuity mistake: After David's class ends, you see the woman sitting next to Berlin standing up and leaving. The camera angle changes and you see her standing up and leaving again. (00:22:25)
Continuity mistake: While Berlin is telling David that she will do anything for a passing grade, you see David putting papers in his breifcase and closing it. The camera angle changes and you see him doing it again. (00:22:59)
Continuity mistake: As David is putting Jamie to bed, you see Jamie in the sitting position getting ready to grab the quilt to cover himself. The camera angle changes and Jamie is now laying down in bed with the quilt pulled up. (00:25:17)
Continuity mistake: When Jamie tells David that he has something important to ask him, the quilt is pulled up to Jaime's chest, but when the camera angle changes to a close-up, the quilt is now pulled down to his stomach. (00:25:21)
Continuity mistake: When David tells Jamie that he has a lot of requests for breakfast, you see Jamie's stuffed animal on his chest being held in place by David. The camera angle changes and the stuffed animal is now seen laying on Jamie's side which David grabs and gives to Jamie. (00:25:44)
Continuity mistake: On Day 2, Bitsey is seen taking notes with her notebook laying flat on the table. David starts talking "off the record" and when the camera angle changes, the book is now folded on the table. (00:45:06)
Factual error: When David is reading the e-mail about his son's custody sent by his wife, the date reported on is Tuesday, 8 Oct 1994. However, that day was a Saturday. (00:48:39)
Continuity mistake: When David is saying goodbye to his wife and son as they leave for Spain, he is standing with his hands on the open taxi door. From the front, he has the left hand on top of the right, but when shown from behind, the right hand is next to the left. This is shown several times during the scene. (00:49:05)
Factual error: The movie leaves the impression that Huntsville, Texas and Austin, Texas are just a short distance apart. In reality, they are at least three hours apart.
Continuity mistake: When Bitsey is checking the videotapes at Dusty's house, the last tape, the one with the red label, falls over when she grabs the second last. As she puts the second last tape in the VCR the last tape is seen standing again. She then searches for any more tapes, but never checks the last tape.
Audio problem: When Constance informs David that he has been put on official "sabbatical" and unofficially released (as a professor), she adds vocally that the vote was "4-2". However, her lips do not move, and the exact vote turnout sounds distorted, because it was edited later.
Factual error: When Bitsey enters the prison for the first time, the sign reads in Spanish "Cierre la puerta fuerta." It is misspelled, it should read "fuerte." The word "fuerta" doesn't exist.
Continuity mistake: When Constance and Gale are making love, she has zero bruises. However, both before and after the scene, there are many bruises - especially on her legs.
Other mistake: Toward the end of the movie when Bitsy is racing to get to the prison before the execution, she has car trouble. She tries the key again before giving up, grabbing the video tape and running down the road. This same "car trouble and desperate race" scene is shown at the opening of the movie, but Bitsy exits the car immediately after it stops. There is no delay to allow for her to try the key again or grab the video tape.
Revealing mistake: The video that Bitsey watches at the end of the movie, we see David walk over to Constance's dead body on the floor and Dusty walk away to stage left of the video camera. David then immediately turns around and walks towards the video camera, staring right at the lens. As he walks closer, the camera slightly pans down to keep him in the shot. The problem is nobody is running the camera. It was on a tripod on a table. Dusty would have to have done a quick 90 degree turn, stood on a chair and gotten set behind the camera in a very short period of time - without shaking the table or the camera.
Audio problem: When Bitsy and Zach arrive at the motel Zach gets out of the car and we hear his door close normally. When Bitsy gets out she visibly slams the door, yet there is no sound.
Continuity mistake: When David is talking to his son about when his mom will be home and what he can have for breakfast, the child's hands change position drastically between camera angles.
Continuity mistake: In Gale and Bitsey's last interview, Gale states that he will be dead by the same time the following day. However, the interviews were each 2 hrs and started at 3 pm, which would make it 5 pm when the interview was over. In the last scene, it is explained that all executions in Texas take place at 6 pm and Gale is pronounced dead at 6:12 pm.
Answer: I believe that she was a plot device to make sure David Gale had nothing to lose by the end of the movie. She then may have felt guilty about casual sex, and tried to get back at Gale. She then later felt guilty about the whole charade, and wrote him a postcard admitting what she had done. Then the postcard is given to the ex-wife to show he was innocent of rape.
Richard Welty
David had asked Bitsy and, presumably, Dusty, to preserve his son's memory of him. So they/he/she forwarded the postcard from Berlin so his ex would know he was innocent of the rape charge. Along with money for his son.