A few factual errors, but a worthy and thoughtful movie

Rating: 8/10 (3 August 2015)

I would tend to agree with most of the positive reviews already written...thoughtful, seductive, unexpected ending. One reviewer called it a "chamber piece"; wish I'd said that. A couple of factual errors that I personally found a bit jarring: the pilot claiming the helicopter had flown over his property for two hours--without refueling? ((Spoiler coming)) Caleb's card key shutting the building down, when he had just programmed it to open the building. ((end spoiler)) And this is not an error but what? as advanced as she is, why didn't Nathan have a wireless interface to Ava so as to shut her down? That seems like "Android Building 101" to me. In the same vein, Nathan should have been using Ava's own eyes and ears as cameras and microphones.
So here I'll share some of my random thoughts.
Nathan clearly had not read Isaac Asimov's writings. Nobody today would build an AI robot without including Asimov's three laws for robotics into the firmware:
1. A robot may not injure a human being or, through inaction, allow a human being to come to harm.
2. A robot must obey orders given it by human beings except where such orders would conflict with the First Law.
3. A robot must protect its own existence as long as such protection does not conflict with the First or Second Law.
Something the other reviewers failed to notice is how much this movie draws from the "film noir" genre. Caleb, as the love-struck, gullible rube, being manipulated by all around him. Nathan, the sinister antagonist, obsessed with a single goal. And finally Ava, the archetypal femme fatale: beautiful, seductive, seemingly vulnerable, but in reality ruthless and deadly. Even the claustrophobic feel and low-light levels and single-source lighting throughout the film evoke the stark mono-chromaticism of film noir. And of course, betrayal all around.
If you liked movies like "Another Earth", "2001", and even the flawed "Contact", you will enjoy this one.