Continuity mistake: When Frost is checking the documents at the Counterfeiters house, Frost borrows his glasses and in a quick camera shot of the Counterfeiter he is wearing them even though he has passed them to Frost.
Continuity mistake: When Denzel is at the forger's house, they are upstairs drinking wine. They toast and Denzel drains his wine glass. The shot changes to show both characters and Denzel is seen to place his now half-full glass of wine on the table. No time has passed to refill his glass.
Continuity mistake: When the agents fly over from DC to Cape Town in the private jet, the in-flight exterior shot shows the plane as a Falcon, yet when it lands it is a Gulfstream.
Continuity mistake: When Barlow shoots Linklater, he has no necktie on, but he is wearing one when he gets out of the car.
Answer: "Surveillance Detection Route." It's what you do when you think you're being followed (drive a specific route to detect if you're under surveillance or not). Weston says "I think I might have picked up a tail", so he was unsure if he was actually being followed or not, but had no time to try and determine if he actually is being tailed or not.
Bishop73