A slight variation on something I picked out before - and wrong for similar reasons. First, if you can see a single contour line on Randi's map then you have better eyesight than the rest of us. The hills on Randi's map are actually well to the north of Dunfirmline in any case. Also, the statistical clustering of ancient monuments has nothing to do with it because the skeptics only had to pick a single monument for the dowser to dowse, which could just as easily have been rural as urban. For example they could just as easily have picked Tintern abbey in Wales, which is in a valley, has one road going past it and is four miles from the nearest town. Third, if you removed all the roads, rivers and contour lines etc. etc. then it might just as easily be a map of somewhere else entirely. There has to be a symbolic (or other?) link of some kind between the map and the physical area to which it corresponds. I'm fairly amazed that the experiment worked because Michael was not given any idea of where the area corresponded to, nor was there a North indicator on the map. Nor was he given any specific information about the kind of ancient monument he was looking for and the grid was at an angle to the cardinal points.I don't see why the presence of the roads, rivers, and contours on the map would be necessary for this kind of dowsing. It seems to me that if he's relying solely on his dowsing instrument they would be inconsequential. What is more likely is that he uses the geographical information to come up with areas where a historical monument is probable to exist, such as a place on top of a hill where several roads and rivers meet. This would greatly improve his chances of guessing correctly.
As any real dowser knows, if you try to apply left-brain logic when dowsing you can be lead astray (especially by a skeptic who might anticipate your attempt at "logic"). This would not really be dowsing at all. Dowsing is about trusting your intuition, not trying to figure things out.
P.S. Tintern is the most famous abbey in Wales and well worth a visit. Its rural location is actually quite typical for Cistercian monasteries as they were instructed to build "far from the concourse of men".
Ian