Whittall was not in court and his case was adjourned to October 25.
Bernie Monk, who speaks for the families of the men who died in the mines during a series of explosions beginning on November 19, 2010, told APNZ it was disturbing that Pike River wasn't going to answer the charges.
"It just brings it home to me that when they went into liquidation they walked away from the men who have worked their guts out for all that time down in the mine and they've just walked away from the families of those men and answering nothing."
Mr Monk said the Government needed to bring a law change that would compel companies and people to answer charges when a person or people had lost their lives.
He said there was a possibility police would bring criminal charges in connection with the explosions.
"It's a start of what's to come and it's just made me realise how the families have got to make sure that safety goes into the mines and let it be a legacy to the men that died in there that this doesn't happen again."
The Grey District Mayor Tony Kokshoorn said today's conviction and news that the mine's receivers would not be fighting the charges was positive.
"It's going to save a long drawn-out battle - the families don't need this.
"This needs to be put to rest and the fact that they have accepted their guilt means we can turn another page now."
He said it would be interesting to see the result of hearings with Whittall but today's results could show him and his lawyers that they were "up against it".
Mr Kokshoorn said a long-lasting court case would do nothing but hurt the families more.
PwC said it would not take place in further legal action because the company was in effect a "bare shell".
"Even after the sale, the company owes substantial amounts of money to both its secured and unsecured creditors.
"We, the receivers have no direct knowledge of the matters which are the subject of the Department of Labour's prosecution.
"Given the amounts still owing to creditors, the receivers do not consider it is in the economic interests of creditors to spend the limited funds available to the company forming a view on the merits of the prosecution or any defences to it."
The company said it was a "pragmatic decision given the circumstances".
VLI said the case was the first time the company had faced health and safety charges.
It said the charges did not relate to the mine disaster, but to a their failure to ensure a contracted drilling specialist had the drill rig there.
"In hindsight, our reliance on (the contractor's) PRC's processes alone is regretted. Our admission to the charges is intended to acknowledge that we could have done more to monitor PRC's inspections of our equipment."
Meanwhile, the Royal Commission into the mine blasts has announced it will not reconvene its public hearings.
Counsel for some former directors and officers of the company had applied to reconvene the Phase Three hearings.
But the Commission said it did not have sufficient evidence to answer its terms of reference and did not believe a further hearing was necessary.
The two-day High Court judicial review seeking a reconvened hearing will begin on September 3.
The Commission is due to report by September 28.
