The explosive residue found on the cars is TATP, short for triacetone triperoxide or simply acetone peroxide, and it is the same non-nitrogenous explosive used in the 2005 London bombings.
Eric Bana and Rebecca Hall spent three months before filming began getting to know the intricacies of the British legal system.
Several extra scenes of Eric Bana's character with his young son had to be shelved. They were set on the river Thames but the weather was so bad and the Thames had a flood warning so it was just too risky to try filming.
The title is a play on words, referring both to CCTV and to a judicial system that takes place behind closed doors.
The film's legal loopholes had particular interest for Eric Bana whose father-in-law is an Australian Chief Justice.