Sorry this is not an appropriate question to ask on a public forum, because this involves legalities of whether you can drive following a health condition diagnosed by a Doctors.
You MUST contact DVLA with the full information, for enable them to provide you with the information you are seeking.
i'm not surprised...
instead of him getting Chinese whispers via 2nd hand advice from someone that appears not to be understanding even the most basic of principles , like its not a fine, even after this being explained several times it cant be....
why dont you get him to come here and READ the advice given in the posts here from post 1 for himself please?
several people have taken the time and trouble to carefully explain things regarding him possibly entering into some mythical contract by parking on someone's private land where someone else claims the first someone has given them permission to sc@m people out of money.