Because given the vagaries of the legal system - and the impetus that may well come on the Hanover parties to seek an out-of-court "no fault" settlement to the FMA's civil action - it is possible the investing public will never get to hear the relevant parties' response to questions raised over their commercial behaviour.
While McArley doesn't spell out exactly to which authorities the SFO will be referring all the evidence it pulled together in its own investigation, it's a fair assumption that accounting bodies will be involved.
The brute reality is, that unless the SFO could muster sufficient evidence to launch a prosecution with reasonable certainty, it had no option but to say so and put the investigation to bed.
The SFO could have left its statement at that point. But, in my view, what is notable is that while McArley says the SFO's investigation did not turn up sufficient evidence to bolster criminal prosecutions, it has raised serious questions.
As McArley notes these include:
The consistency between the overall view of the nature and financial condition of the (Hanover related) companies disclosed to investors in the period from December 2007, and the actual position of the companies.
The solvency of the companies at the times that dividends were paid during the six months immediately prior to the suspension of payments to depositors in July 2008.
The propriety of a number of transactions entered into in the three months immediately prior to the suspension of payments to depositors that appear to have provided little or no benefit to the companies, while conferring significant benefits on the related parties.
The accuracy of the valuation of the companies' assets in the financial statements supporting the Debt Repayment Proposal put to investors in November 2008.
At issue now is whether those issues will be probed in a public fashion, or will they end up swept under the carpet?
This is relevant given the prospect that the Financial Markets Authority could ultimately negotiate an out-of-court settlement with named Hanover parties in the separate civil action.
The SFO says much of the evidence it collected during its investigation has already been referred to the FMA. The FMA's proceedings, launched under the Securities Act, are against former chief executive Mark Hotchin, co-founder Eric Watson, and former directors Greg Muir, Sir Tipene O'Regan, Bruce Gordon and Dennis Broit.
The FMA is seeking compensation for investors who put $35 million into Hanover Finance, Hanover Capital and United Finance between December 2007 and July 22, 2008.
When the FMA first flagged its intention to launch civil proceedings in relation to Hanover, chief executive Sean Hughes said he was "not ruling out the possibility" of a commercial settlement.
"It could well be likely if the defendants who we are proceeding against have insurance coverage or sufficient assets to satisfy a judgment - and one of them most certainly does - it would seem to be more pragmatic to go down that path," he told me in an interview in late 2011 ahead of the formal proceedings being launched.
Hughes said then the FMA would have to see the response.
It's since become apparent that the former Hanover personnel cannot rely on insurance giant AIG to come to the party.
Hanover Group Holdings lost a High Court fight on that score over a policy worth up to $20 million - although it has lodged an appeal.
AIG did not accept that the directors and officers liability policy that Hanover took out in November 2007 provided for claims associated with two prospectuses released by Hanover Finance Limited and United Finance Limited. The relevant High Court judgment may yet be appealed.
But with the insurers unwilling to backstop the directors in the civil proceedings, they will have to rely on their own financial resources to fight the action and make good on any financial damages if they defend the FMA action and lose.
This is one reason why the High Court has prevented Hotchin from disposing of some significant assets.
The SFO's decision does provide the Hanover directors with clear water to consider their positions. The prospect of criminal litigation no longer hangs over them.
If they are sure of their position - and each of the named parties has said so - they will simply defend the FMA action.
SFO director Adam Feeley started the ball rolling some 32 months ago. In a statement on the background to the investigation the SFO said that it upgraded its investigation into the group as "following the collection of further information the Director determined that there was reasonable evidence to believe an offence involving serious or complex fraud may have been completed".
But McArley makes clear he did not reach his decision in a vacuum - consulting with Crown Solicitors, leading criminal Queen's Counsel, and the Deputy Solicitor-General to confirm his decision.
What's interesting from McArley's press release is the SFO spent only 120 hours - equivalent to three 40-hour weeks - interviewing various people in relation to the investigation.
The issues are complex and deserve not to end up swept under the carpet via a negotiated settlement to the civil case.