technically, money is a representation of debt.
An unpaid fine is also a debt.
Paying off one debt with more debt is fraud!
Therefore your friend is unable to make good any fines by use of conventional currency, so the figure given can be rejected.
Also, many governments are actually private corporations (dont know about denmark)
private corporations operate under commercial code or 'contract law'.
As such, contractual obligations cannot apply to non-corporate entities (living individuals), unless that individual has willingly entered into a fully disclosed contractual agreement to abide by the company laws (most of us havent)