Council chief executive Andrew Newman spoke of his frustration at the expense, however noted there had been "fairly substantive levels of cost" for others involved in the inquiry.
The departing executive said it was an "enormously frustrating expense" given where council could have better applied the resource, and time.
Councillor Tom Belford questioned how this expense could be characterised, as "to a lot of people the characterisation of it would be that we spent $700,000 to manage the placement of blame in this project".
The question of what had been bought for $700,000 was repeatedly asked, he said.
"I presume what we bought was an expensive effort to shift, or make sure blame did not fall on us that we feel we did not deserve. Is that an apt way to characterise the spend?"
Mr Maxwell disputed this, saying external legal counsel had been valuable given the council did not have such internal resources.
"I have lost sight of absolutely just how many steps, and processes, and iterations of this there has been," he said. "In the absence of legal advice we would have been absolutely lost at sea."
"I share the frustration thinking about what I could have done out in the field with $700,000 but it was, in this case, unavoidable."
Although the council "could get into a fight over this", council chair Rex Graham said it had to learn from the experience.
The council would not be able to receive insurance for these costs.
Costs were expected to be "substantially less" for the second stage of the inquiry, which the council had "tentatively" engaged a locally based planning consultancy to assist with.
On the prosecution against the Hastings District Council, the regional council spent nearly $15,000 on legal fees to March 16.
In comparison the district council spent $71,000 ,this is subject to an insurance claim.
This prosecution ended with the regional council dropping its two charges against the District Council, who conceded the breach of resource consent conditions and agreed to not contest two infringement notices, resulting in two fines of $500 apiece.