Then in June, he "personally solicited a donation" from Mr Dotcom, who subsequently paid two $25,000 donations into Team Banksie's account. Finally, in September, Mr Banks "personally solicited" help from another unnamed donor who agreed to fund some radio advertising.
Each of these donations was listed as anonymous on the return, which was "compiled by a campaign volunteer" and then signed by the candidate.
Mr Banks "sought and received confirmation that it was an accurate return of his expenses before signing and transmitting the return", says the report, and the police were "unable to establish that Mr Banks had the necessary knowledge that the donation[s] had been recorded as anonymous ..." So, Not Guilty.
I can't get too worked up about Mr Banks wriggling off the hook. He was playing by the rules of a badly flawed system. In all, $520,086 of his $948,937 funding was declared "anonymous". His successful rival, Len Brown, recorded $499,000 of his $581,900 haul as "anonymous".
It beggars belief that big donors to the inaugural mayoral campaign for the Super City didn't make sure that the person they were backing knew exactly how generous they had been, and what their priorities were.
If I'm making the process sound mercenary, that's because it is.
Mark Hanna, the father of American presidential campaigning, summed it up a century ago when asked what was important in politics. He said: "There are two things. The first is money and I can't remember the second."
In democracies like ours, the ongoing battle is to keep this flow of money to politicians transparent and in check. Invercargill City Council byelection candidate Allan Arnold was reminded of this last week, when ordered to remove his offer on Facebook of mulled wine for all those who voted for him.
A cup of wine, a $50,000 donation - it's all part of the same game. At least the wine "bribe" was out in the open.
After expat millionaire Owen Glenn revealed embarrassing details of his "anonymous" donations to both Labour and Winston Peters back in 2008, our parliamentarians reluctantly legislated to outlaw all but the most modest of anonymous donations.
Local government politicians escaped that blast of revealing fresh air.
After Kim Dotcom's revelations this year about his gift to the Banks campaign , the Government promised to update local election legislation and "bring the two regimes together". It said it was just a matter of finding a gap in a busy legislative programme, but was aiming for later this year.
The police decision this week to finger the "volunteer" and not the politician should be the nudge it needs.
