Her clients, and Doug White - by appearing while others sat quietly in the shadows - had shouldered the criticism, and done that with dignity, she said. They had not "cowered in other countries''.
"My clients have not shirked from their responsibility, they have not hidden.''
There was no certainty as to what caused the mine to explode, or even where the blast had occurred, she said.
Sixteen months after the tragic explosion, and after extensive police and Department of Labour investigations, plus 10 weeks of hearings, "we are all left speculating''. There was no conclusive evidence that something the men did, or did not do, had caused the disaster. One man underground that fateful day may have been responsible.
She noted that the mine had been planned before her clients became directors or managers, with the aid of a raft of experts upon whom they relied.
Ms Shortall spent some time detailing some of those experts.
Fan manufacturer Flakt Woods proposed putting the main fan underground, and the Department of Labour did not, in the three years that it was planned, take exception to it.
Consultants URS did not query the second vertical escapeway, and tunnel contractors McDonnell Dowell had never raised concerns about its men working in a mine with a shaft as a means of escape.
The Department of Labour - under fire itself and on the defensive - had gone on the offensive and charged Mr Whittall, she said.
Mr Whittall was the "fall guy'', who had moved to the Wellington office nine months before the disaster.
However, commission chairman Justice Graham Panckhurst cautioned her: "We are conducting an inquiry ... we are not here to try your clients.''
In a two-hour, wide-ranging closing speech, Ms Shortall also:
* Claimed that Solid Energy chief executive Don Elder, who was critical of the coal resource, made the comment to drive the price down before buying the mine. Solid Energy says that suggestion was "offensive''.
* Admitted there were shortcomings in Pike River Coal's systems and information "fell through the cracks''.
* Said it was still unclear to her whether police would prosecute, but she had advised her clients at times to be silent.
Mr Whittall was actually in London at the time Japanese hydro mining expert Oki Nishioka alleged he told him of his safety concerns.
* Said the Department of Labour had not found any evidence that managers knew gas sensors were being tampered with underground.
Meanwhile, commissioner Stewart Bell said mine manager Steve Ellis failed his manager's exam three times in Australia, but got his ticket in New Zealand in a matter of weeks, while Mr Ward, the "conduit to the board'', was not a mining person.
In his closing remarks, Justice Panckhurst said today was a milestone, "perhaps more so for participants and families''.
The commissioners were in the midst of the policy work and next week they would determine the policy direction.
The commission remained open for business, and was open to new developments.
He said there was still a great deal more work to be done in reaching final positions, and formulating recommendations.
Bernie Monk, spokesman for the families of the Pike River dead, criticised Ms Shortall for using her closing argument to deflect blame away from her clients.
"She treated it mainly as a court case - trying to pass the buck. It's as if they don't want to own up to everything."
Outside the court, the families posed for a group photograph at the close of the Royal Commission.
Mr Monk said he had confidence commissioners would create a comprehensive and fair report.
The families would battle for its findings to be implemented across New Zealand, he said.
"History has been made but the battle will still go on. We're making sure that when the commission submits its findings they are actually followed through on by Government departments."
"It's business as usual for us. We meet every Wednesday. We're meeting tonight."
The most moving moment of inquiry came when families were called to give testimony about the loss of their loved ones, Mr Monk said.
He was still angry at the lack of support given to families when Pike River Coal went into receivership soon after the November 2010 blast.
"It will be in my heart the rest of my life that people walked away from us."
"There'll never be any closure until somebody I trust looks me in the eyes and tells me 'Bernie, we've done all we can to get your son back'."
