brilliant but. . .

The car is seen to be taken out of the Forth on the Fife side of the river with the Rail Bridge to the left, given that they came from Edinburgh, firstly it seems stupid that they would cross the river; and secondly, if they did so surely the police would contact the Road bridge authority and they would then enevitably find out that Agnew and Geddes were driving.

sorry, this really does not detract from the fact that this was one of the best dramas on British TV in recent years, it's just that it really started to bug me because it would have solved the whole murder and it seems like such a basic mistake.
I'm not really this sad, I just thought I'd mention it.