If there is any good news at all, it is that having paid to recover the vehicle, your friend has now paid all there is to pay, so can take the matter all the way to adjudication at no extra cost. However, whilst you can submit mitigating circumstances to the council, you'll also need to state that the towing of the vehicle was totally disproportionate, and that a PCN would have sufficed. Adjudicators cannot rule on mitigation, so they can only look at the penalty, probably under statutory grounds of "the penalty exceeded the relevant amount in the circumstances of the case",
