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.
The boat house shown several times throughout the movie was a mock-up building. The location is cobbled car parking spaces for local residents next to the Battersea Saint Mary's Church.
The film's legal loopholes had particular interest for Eric Bana whose father-in-law is an Australian Chief Justice.
Eric Bana and Rebecca Hall spent three months before filming began getting to know the intricacies of the British legal system.
The title is a play on words, referring both to CCTV and to a judicial system that takes place behind closed doors.