Thank you Craig for confirming my view.
LoL
The basic tenant of the officers defence as reported was that he was familiarising himself with the vehicles handling and performance, and honing his driving skills.
Based on that premise, and without any doubt in my mind the performance and handling can be best explored under controlled conditions, for example, finding the breakaway point at which the car begins to slide, the degree of over or under steer and many other aspects of handling at the limits. It would not be safe to attempt to explore any of these on the public roads, simply because if it goes wrong, then there is less room to provide corrective action or if it can't be controlled then the consequences could be dire.
Such learning activities should be carried out under controlled off road conditions. The training to manage driving situations - how to manage a skid, cadence breaking, acquiring maximum performance through the gears etc. There is no need for such familiarisation of extremes to be performed on public roads.
The other dangers that you correctly mention; such as camber, aquaplaning etc are so variable across our roads that you cannot reliably provide the full range of experiences to any driver. These conditions may also naturally limit what the driver can do to explore the vehicles performance envelope, so the driver may not be able to extract and fully understand the true capabilities of the vehicle.
It will always be up to the driver to decide how they will negotiate any particular situation when it arises, but knowing the full potential of a car will enable the driver to make a better-informed decision.
There is a need for Police driver training to be carried out on the Public roads, if possible the driver should familiarise them selves with roads in their patch, but that does not require excessive speed.
Clive, sauce for the goose is sauce for the gander so, I take it that your one years experience is now 40 years old!
Nuff said, as with other debates, discussions, tirades & diatribes we have a difference of opinion.
So here endeth the lesson.