Hager's book cites Slater's emails which leave the reader to draw only one conclusion - that Slater was tipped off about the material and told how to request it so he got it quickly.
Only officials or staff in the SIS, the Department of Prime Minister and Cabinet or the Prime Minister's office - all of which fall under John Key's responsibility - could be culpable. If someone from either of the first two departments was in collusion with Slater, then that amounts to a serious case of the polticisation of the public service.
If the latter office was orchestrating the release of the material, then it was being done for political purposes and was an abuse of power.
Gwyn has now deemed there is "sufficient public interest" to justify her holding her own inquiry to get to the bottom of what happened.
It is a hugely significant and - given the current acute political sensitivities surrounding Hager's book - unprecedented step for her office to take.
Gwyn is to be applauded for having the gumption to dive into the deep end of a political brouhaha of such messy but high-stakes proportions.
It seems unlikely she will have enough time, however, to complete her inquiry and release her findings in the little over four weeks left until the election.
And for that, the Prime Minister - locked in the political fight of his life on a number of fronts - could yet end up being extremely grateful.
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