The casino had to pay out $300,000 over the misunderstanding.

An Auckland SkyCity worker has won his job back after being fired over a mix-up with a customer who was betting millions of dollars.

A foreign visitor was playing baccarat in one of the casino's individual gambling salons, reserved for high-value customers, in the morning of February 17, 2016.

She had been gambling there for nine days. Employment Court judge Mark Perkins said it was estimated she had lost anything from $9.5 million to $12m dollars.

During a shift briefing, table games trainer Keith Hayashi was told that the table limit for a baccarat "any pair" side bet had been reduced from $10,000 to $5000 in one of the salons.

READ MORE: SkyCity Casino worker fired for $310k payout to high roller

He, and other workers, mistakenly believed it applied to the one in which the woman was playing.

When someone has been betting above the maximum, they are entitled to a refund of the extra bet, minus any winnings.

In this case, that worked out to $310,400.

SkyCity argued that Hayashi approached the woman and told her she should get a refund, and how much. He disagreed with that assertion and said she was also told by the table games area manager. His version of events was corroborated by others.

When it was discovered that her betting limit had not changed, and she was not due a refund, the situation became difficult. The player demanded the money and was later given it as a goodwill gesture.

Hayashi was dismissed and the Employment Relations Authority backed SkyCity. He then took his case to the Employment Court.

"While Hayashi conceded that he could have handled the matter better, his motivation was to first calculate what might be involved and then persuade senior management to consider some form of ex-gratia payment," Perkins said in his Employment Court judgment.

Correspondence between the chief executive and the president of international business made it clear that someone would take the fall for the payout, Perkins said, and it ended up being Hayashi.

While giving evidence, the table games manager told the court it was fair to describe those involved as "running for cover".

"Looked at objectively as the court is required to do, the steps taken by SkyCity in these circumstances leading eventually to Hayashi's dismissal, were not the actions which a fair and reasonable employer could have taken in all the circumstances," the Employment Court judgment said.

"The reasons for the dismissal and the process were particularly undermined by incorrect information being given by the table games manager and her then being allowed to participate in part in the disciplinary process."

Hayashi wanted his job back – saying he was near retirement and it would be hard to find another role. He also asked for reimbursement for lost income, compensation for hurt and humiliation of $25,000 and costs.

The Employment Court granted him those requests, but reserved costs.

The judgment said the $25,000 requested was a modest claim and he should also be given compensation for all wages or salary lost, including any increases he would have had had he remained in employment.