If you're a car reporter driving a loaner vehicle of one of the most sophisticated production cars in the world, you shouldn't really be surprised that the vehicle has data logging. I'd be surprised if most modern luxury cars don't have some level of logging in their systems - I'm pretty sure even my 2007 mid-priced car has logged usage data accessible to the dealer on usage patterns when I take it in, because they've told me things like "you have been driving the car only very occasionally."
It's true they could guess that, but the issue was the interval between usage, not the mileage. As I understand it, pretty much every car built in the last 10 years does some degree of logging, if only to provide a record of what the car was doing immediately before a crash. For cars with more electronic systems - stability, ABS, and certain automatic transmissions - they do more logging so that dealers can debug problems.
For example, my car also has an adaptive transmission system that collects data on my driving behavior and uses it to improve when the car chooses to shift. Sometimes folks have the dealer erase this data so the car "re-learns" to shift fo r them.(http://www.bmw.com/com/en/insights/technology/technology_gui...)
