Stupidity: Why would they drive all the way to Marylebone Railway Station in central London when Southbury Road station is only a thirty-second drive away?
Stupidity: During the movie, the bad guys keep the main character alive and free to roam the facility at will (even if they made him sign an incriminating form at the very beginning stating he's an inmate) doing absolutely nothing to restrict his freedom till the very end - he even retains personal effects like his broken Rolex and lighter, his wallet full of cash! He breaks into every forbidden area, picks up fights, damages property, escapes multiple times and 'corrupts' the person the whole facility is built for. He is worth absolutely nothing to them and has nobody waiting for him or that will look for him.