Reopening the Royal Commission of Inquiry into the Pike River Mine tragedy in order to cross-examine more witnesses would be pointless because the same evidence from other witnesses has already been heard and questioned, a court was told today.
The mine's former chairman John Dow and former chief executive Peter Whittall are in the High Court at Wellington seeking to have the commission hearings reopened so evidence from three workers can be heard and cross-examined.
Former Pike River Coal Ltd technical staff member Udo Renk and middle managers Terry Moynihan and Greg Borichevsky gave written statements to the commission three months after the public hearings finished in Greymouth and a request to reopen the hearings so the men could be cross-examined on their evidence was declined.
Cheryl Gwyn, appearing for Attorney-General Chris Finlayson, told the court much of the work by the commission happened outside of the public hearings.
"A high degree of deference is owed to the commission's choice of procedure."
Ms Gwyn said the written evidence from all the witnesses had been previously addressed by other witnesses before the close of the public hearings.
"It's plain that it's not new evidence... and in that regard I can't understand that they've been surprised by the evidence."
She said because of that, the evidence had already been tested.
She said the applicants wanted to "expose" an apparent conflict of evidence between another witness and Mr Borichevsky.
It was up to the commission to decide whether evidence had been sufficiently tested, she said.
The applicants had the opportunity to put something before the commission noting apparent conflicting evidence from Mr Borichevsky but they chose not to do so, she said.
Justice Ronald Young said that while he did not give a lot of weight to the applicants' arguments, there was potential implications to fair trial rights.
The lawyer for the commission James Wilding said the Commission couldn't take such an "arid view" and only focus on the rights of the applicants.
He said in some cases it was appropriate to deal with conflict of evidence by reopening the case, but not in all circumstances.
The lawyer representing the Engineering, Printing and Manufacturing Union, Nigel Hampton QC, said earlier today the commission's process was fair.
He said it was a "paper-driven" inquiry, with more than 360,000 pages of evidence, most of which had come from the applicants.
If all people who supplied paper evidence also gave oral evidence, the commission would be sitting for the "undefinable future", he said.
"Where is the unfairness in the process? I would suggest there isn't any."
Whittall and Pike River Coal face a total of 21 charges, brought by the Department of Labour relating to a series of explosions in the mine that killed 29 workers in November, 2010.
In July a Pike River Mine contractor Valley Longwall International (VLI) pleaded guilty at the Greymouth District Court to three health and safety charges.
The hearing is due to finish this afternoon.