Dissociative Identity Disorder, formerly known as Multiple Personality Disorder, is a highly controversial diagnosis, with many arguments against it being anything more than an iatrogenic disorder -- in other words, caused by the therapy/therapist itself. Most notable amongst these arguments is that unlike other psychological disorders, DID is not observed outside of treatment with certain select clinicians, all of whom already believe in DID. What has been observed across all clinicians and researchers, however, are examples of confirmation bias, persuasive interview techniques, demand characteristics, and the oftentimes overwhelming urge to please demonstrated by patients in general. In addition, early North American works (DID is an overwhelmingly American disorder, yet another point of contention for the pro/anti-DID debate) which are seen as having started the DID diagnosis trend have been debunked in recent years as primarily fictitious stories, written to sell books. As controversial as the diagnosis of DID is, many feel that there may be some degree of negligence on the part of the producer(s), the director, and the film company as a whole for not employing a disclaimer as well as affording equal time to opposing expert viewpoints.
The film's explanation of Rickey Ray Rector, who incurred some degree of brain damage after committing multiple murders when he shot himself in the temple, is somewhat manipulated to cast Rector in a sympathetic light. Rector was, despite his minor self-inflicted injury, judged to be competent to stand trial, as his brain damage was minimal and he expressed an understanding of the charges against him, the difference between right and wrong, and what the death penalty was on multiple occasions.