John Armstrong: Gravity of situation seems to escape Mr Sensible's notice

Dunne is keeping mum about the email contents as he says that would breach the notion that communications with MPs remain confidential. Photo / Mark Mitchell

Maybe the enormity of it all has yet to really sink in. Maybe Peter Dunne is in a state of complete and utter denial. Maybe in his mind he has convinced himself that he did not leak the Kitteridge report on the GCSB despite the evidence - although circumstantial - pointing unerringly in his direction.

You had to wonder if it was the real Dunne who fronted yesterday for what was a pretty bizarre press conference which followed the Prime Minister's acceptance of the United Future MP's resignation from John Key's ministry.

Dunne did not carry the demeanour of someone whose world had just come crashing down and whose near three decades of toil at the parliamentary coal-face had just ended in disgrace. It was Mr Ordinary trying to explain the extraordinary. It was Mr Commonsense struggling to make sense of the senseless.

He read a brief statement before adding he would take only two questions.

He took at least 20. Through it all, he continued to protest his innocence and insist he had not leaked the report to the Dominion-Post's Andrea Vance.

With Vance and her employers adopting the standard response of never commenting on sources, it is a fair bet the answer as to who leaked the document lies somewhere in the pile of 86 emails Dunne exchanged with the journalist over a 14-day period.

Dunne, however, refuses to reveal the contents of them all because he says that would breach the notion that communications with MPs remain confidential.

Yet surely if he is innocent as he claims, he could have shown the contents in confidence to David Henry, the former high-ranking public servant who conducted the inquiry into the leak.

Dunne says he could not breach his principle - one, it seems, that was not so inflexible as to stop him providing Henry with an edited text of most of the 44 emails that he sent to Vance. But Henry wanted access to the real thing. When Dunne refused, his fate as a minister was effectively sealed.

There are other damaging questions. Why - as Dunne suddenly admitted during his press conference - did he canvass the possibility of leaking the Kitteridge report?

Why did he tell Vance he was about to be briefed on the contents of the report?

And why were he and Vance exchanging as many as 23 emails a day while Dunne was on holiday in the United States? Was it infatuation? The ex-minister says it wasn't.

The public may never know exactly what happened. But Henry's short report is long enough for people to be able to draw their own conclusions.