it all seesm a bit odd to me, surely it is a case of , if you are not using your vehicle for any kind of 'event' and you ar not causing damage by reckless behaviour or negligence, then surely you are covered?
I agree. I think they've just made a mistake. I reckon you should be covered for 3rd party risks in any public place - including offroad public places, such as Sainsbury's Carpark.
Cheers
Andrew