I can't see the problem. Surely if a 4 x 4 wants to do a bit of off roading and there appears to be a track up there, why not.
All this talk of 'small minded' and 'stuck' it looks perfectly at home to me and, unless the driver has broken any by laws, then why not indeed.
It would be interesting to know what the Police have charged the driver with,
1. 'Spirit of adventure'
2. 'Cheating the usual method of ascending said mountain'
3. 'Abandoning a perfectly good off road vehicle in a public place' or
4. 'Doing something hundreds of others have thought of but too scared to do'