The son's behavior would get him into trouble with Adult Protective Services in many states, but then again, he's a lawyer himself. He gives the law profession a bad name with his own "power of attorney abuse." The film could be seen as making the case that it is too easy to give adult children power of attorney when elders start to lose it.
The DVD has a featurette "That Tennessee Sun" and another short (35 min) "Arts & Crafts" about the making of the film. Both show the heavy gear and professionalism involved in making even a "small" film. They make the case that shooting for theatrical release is different from filming for TV, even though modern plasma TV and Blue-Ray bring them together. The short talks about the "Satie-like" piano score by Michael Penn, which curiously invokes distant echoes of southern rural life.
The cast interviews talk about the aging of the population, and the clash between "gentry" (Abner) and working classes, each with their own delusions, particularly in rural areas. Neither Abner nor Lonzo are capable of running the farm.