This movie is one of the most shocking things I've seen and it's all because it's a true story of a so called scientist that has lost his humane side and enjoyed conducting a psychologically damaging experiment.
The lack of control on the guards shows that Dr.Philip was fascinated by the horror and cruelty human kind can create even in a simulation. The fact that he chose an ex-prisoner as a consultant shows that this experiment lacks all credibility because the ex-prisoner wanted to subject his negative experience on innocent students. A chilling movie until the last seconds!!!!