UPDATED 7.11pm: The boss of Pike River Mine at the time of the 2010 disaster has again escaped his day in court.

Peter Whittall originally faced 12 charges from Health and Safety watchdog Worksafe, but the charges were dropped and a deal was cut for Mr Whittall to pay $3.41 million to the victims' families and two survivors.

Two families applied to the High Court for a judicial review and lost the case.

They appealed and today the Court of Appeal released it's judgment dismissing the case, saying the decision to drop the charges was lawfully made.

The court says Worksafe was entitled to consider a reparation payment as one factor in deciding whether or not to pursue prosecution further.

It says even if the decision had been shown to be unlawful, it would not have been set aside as payment had already been made to the families.

Lawyer for the two behind the case, Nigel Hampton, QC, told Larry Williams the Court of Appeal's reasoning was slightly odd. He said the Court claims the payment to the families wasn't a bargain.

"It walks like a bargain, it speaks like a bargain, in my mind it was a bargain," Hampton said.

He said the two families are disappointed, and they'll look at taking the case to the Supreme Court.