[j-a-a-p]

In my country the tax law has a reversed proof clause. Meaning, you are guilty until proven innocent. This clause is activated after you get caught, or even when you did not comply with administrative requirements. Other countries have similar clauses.

So in this case, if you have hard proof, meaning a proper administration, fuel tickets, etc. Which you all don't have, there is basically only a central milage database and ownership records that can hedge your damage.