The man who spearheaded the Pike River Coal mine left the project described as his "baby" after falling out with his board over performance problems, an inquiry has heard.
Former Pike River chief executive Gordon Ward played a leading role in setting up and selling the West Coast mine until his departure less than a month before it exploded.
He has been criticised for refusing to appear at the Royal Commission of Inquiry into the disaster.
Pike River Coal board chairman John Dow this afternoon told the inquiry he had been asked to step in as a mentor to Mr Ward in 2010, after taking issue with him overpromising and under delivering on coal extraction targets.
His review of Mr Ward's performance found multiple performance problems that went unresolved until August last year, he said.
"I couldn't... for the life of me understand why it was so important to Mr Ward to keep assessing at the optimistic end.
"Mr Ward subsequently left Pike River Coal."
Mr Dow said when he signed on as board chairman, he understood the mine was Mr Ward's "baby".
Meanwhile, he defended Mr Ward's replacement Peter Whittall as a competent and capable manager.
Mr Whittall is facing Department of Labour charges over his role at the mine leading up to the deadly explosion last November.
But Mr Dow - an experienced and respected miner - said he was drawn to Pike River Coal because of Mr Whittall's presence.
"I was impressed particularly by the calibre who was running the show on site - that was Peter Whittall."
Criticisms of Mr Whittall's "autocratic" management style from former mine safety manager Neville Rockhouse were unfair, Mr Dow said.
"I wouldn't have described it as autocratic at all. Peter is a very competent and capable person.
"I wouldn't describe it as autocratic no."
'That mine is going to go'
Earlier, a British miner with 35 years experience revealed he told his wife "that mine is going to go" before leaving his job at the Pike River coal mine.
Albert Houlden, a former lead hand at mine contractors McConnell Dowell, left the mine in April last year to take a job in Papua New Guinea.
Before he left, he told his wife, "that mine is going to go".
When his old job was offered to him on his return, his lingering fears about the mine led him to take a job with rival company Solid Energy instead.
"I just didn't feel safe.
"As much as I liked working at McConnell Dowell, I hated working at Pike."
Poor communication between those working inside Pike River was a danger, Mr Houlden told the inquiry.
In one case, he found gas levels spiked "off the scale" within three hours of his team starting drilling.
He evacuated all his workers before re-entering the mine with a deputy to find what was causing the problem.
It was revealed a team elsewhere in the mine had released a valve that was pumping raw methane and water into the atmosphere without consulting him.
Another incident saw his team's ventilation shut off without warning, leaving them breathing in high levels of carbon monoxide.
"I couldn't get my head around why they weren't informing the company or us on shift. Why they weren't warning us. It was if it was carte blanche and they could do what they wanted.
"It was as if everybody was their own independent unit."
Mr Houlden said the lack of experience in the workforce at Pike River was also a major concern.
He said young men at the mine were getting paid "a lot of money for doing very little" while the mine was lagging behind its production targets.
When production bonuses were introduced, their work rate increased to a speed beyond what they could handle, he said.
"They were going 200 miles and hour but their education was still no better.
"They were going from dawdling about standing about... to come on, let's get this done. I don't think they could deal with the production speed. That's the difference you found up there. It was a crying shame because there were a lot of good boys up there."