So National leader Simon Bridges has been able to interrogate Ardern about Curran, her Gmail use, her handling of claims of staff bullying by Meka Whaitiri and differences of opinion between Labour and NZ First.
There is little Labour can do in response, although Chris Hipkins did manage to get in a jab about Bridges being "two snapper short of a resignation" – a reference to former Labour leader David Shearer's stunt holding up two dead snapper in Parliament.
Shearer himself was a dead fish soon afterward.
The hunt for the leaker is now progressing in the hands of PriceWaterhouse Coopers and Simpson Grierson.
That does not mean National's MPs are happy to leave it to the experts.
Among the MPs it remains an item of speculation and rumour.
Names are being bandied about with no real evidence – and Bridges needs to put a stop to that.
False accusations can be as damaging as the leak itself.
They add to suspicion and mistrust. Suspicion and mistrust lead to disunity. Few things can bring an Opposition to its knees faster than those things.
If that leaker strikes again, things will get grimmer for Bridges.
Such problems are inevitably more damaging in Opposition than in Government where a Prime Minister tends to be inoculated from disunity by virtue of their place in Government. That applies at least until polling drops.
For nine years, suspicion and mistrust infected the Labour Party in Opposition.
It took out Phil Goff, David Shearer and David Cunliffe. It was not until Andrew Little came along that caucus bucked up its act – not that there were many of them left by then.
While Little could not persuade the wider public of that, Ardern benefited from it.
Over the same nine years, former Prime Minister John Key churned through ministers apace without losing any of his own power or caucus unity.
He did it partly by dint of keeping hope alive for backbenchers hoping to become ministers – and mercilessly culling average ministers to occasionally deliver on that hope.
A hopeful backbench is a loyal backbench.
In that respect, Ardern has a vacant seat in Cabinet – and needs to be careful what she does with it.
By rights and merit it would go to Kris Faafoi, who has inherited Curran's portfolios of Broadcasting, Communications and Digital Media.
Curran's demise has left Faafoi with a pile of extra work without a seat around the Cabinet table to go with it.
The only reason for that seems to be that he is a man. Ardern has made it a goal to increase the number of women in her Cabinet.
There are now just five Labour women in that Cabinet to 10 Labour men.
The only woman minister outside Cabinet is Whaitiri, who may have been moved up but whose future endeavours may be blighted however the employment investigation turns out.
It is a noble aim and not one Ardern intends to give up on.
The trouble is it leaves the men in the backbenches with very little hope of getting into Cabinet.
Nonetheless despite overwrought gasps of "weak leadership" from Ardern, recent events will do no real damage to her.
Inexperience has been a factor – but that is a short term affliction. A visit to New York in a fortnight will be a further balm for her leadership.
As for Bridges, Maori Language Week has delivered him a helpful investigative tool for his leak hunt.
That is the Kupu app, developed by Spark.
Point a phone camera at something, and the app comes up with the Maori word for it.
Bridges is no doubt stealthily pointing it at his MPs hoping the word "kaiwhāki" [leaker] pops up.
It would be just as robust an investigative approach as the rumour and speculation currently whirling around.
