When Luther drives through a fence, his front windshield
is smashed. The next scene (at night) the windscreen is whole again.
The blood on the VW Beatle windscreen has remained liquid, something like eight or more hours after the crime was committed.
In the opening scene, they are bowling in the UK, but all the lanes have US flags hanging above them. This is because the bowling alley want to have a US feel, like 50s diners.