I have heard that, but if he's been knowingly told to stop pressing on with these random fines due to his lack of knowledge, then it's in his lap. QLD police have made their position clear to him, so then it's down to abusing his power and knowingly depriving someone of money. QLD police aren't in a position to know if he's still doing it as most people cop the fine, have a whinge and don't take it further.
If he's acting unlawfully then QLD police won't have a bar of it when it comes down to recouping money, they'll actually advise you to take it to small claims. Unfortunately they can't be fully responsible for the actions of their employees, much like health and safety is down to the individual. Companies aren't liable for unsafe acts of their employess.