Should the part have gone to Amber Heard?

After all, she is a Texan. Drives a pickup and all. She could have glammed down Charlize style. But maybe she is too shallow for the subject matter. Abbie Cornish definitely has the goods for the serious stuff but her accent doesn't sound Texan at all. Hardly sounds American! I would be interested to hear what a Texan thinks. Another plus for Abbie is she can smoke for real when she has to, not clearly and stupidly fake like Amber.