When Gene Hunt's Audi catches up with the blue Dolomite driven by Thordy, the Quattro's windows are up until the final part of the chase where he does a 180 degree turn in front of the Triumph, in which scene the driver's window is half down. Then it's up again as he gets out, and then both front windows are down as Gene and Alex get in and head for the prison.
The gun which Viv is being threatened with is empty in close shots (the clip clearly spent and the chamber open) and loaded in wide shots.