Dunedin city councillors were ''railroaded'' into their decision about the Frederick St car park, and given inadequate information about the risk of pulling out, Cr Lee Vandervis says.
Cr Vandervis has taken issue with the Dunedin City Council for presenting the decision last week as ''unanimous'', and the council has admitted that was wrong.
Cr Vandervis said he regretted not having his vote recorded.
''I just basically caved in, and I'm sorry that I caved in.
''I wish I'd fought it right to the end,'' he said.
The discussion and decision were held behind closed doors, and councillors were prevented from speaking publicly.
Two councillors - Andrew Whiley and Damian Newell - were informally reprimanded for speaking to the Otago Daily Times about the deal, the ODT understands.
The Accident Compensation Corporation (ACC) has been given a 12-month exclusive due diligence period with a view to buying the car park to build a multi-storey building.
To do the deal, the council reneged on its previous undertaking to earmark the site for the Dunedin Hospital redevelopment.
Cr Vandervis said councillors who were anxious about turning their back on the hospital development were reassured the council could always pull out of plans to sell the land.
''I believe councillors were railroaded into a decision.
''The agenda paper didn't make clear whether or not we were committing to anything.''
ACC's lawyers would not take kindly to the corporation spending money on due diligence only to be turned away from the sale, Cr Vandervis said.
''They would throw the DCC for a loop. The DCC would be liable for all their costs.''
The lack of legal expertise around the council table was showing, he said.
''When you've got a council with no lawyers on it, and the staff saying it doesn't really commit you legally, it's easy to fold.''
''If [former councillor] Hilary Calvert had been on council, I believe her legal expertise might have actually swung that vote the other way.
''I think it's a slap in the face to the hospital in particular, but also to the university.''
Cr Vandervis said the deal was short-sighted financial decision-making.
The university envisages a precinct linking its campus with the new hospital, and it expressed disappointment about the ACC deal in the ODT last Saturday.
A Dunedin commercial real estate agent, speaking anonymously, estimated the likely current market value of the 3195sq m car park at between $4 million and $5 million.
''It's hard to put a number on it because it does have scale.
''We've sold sites for residential development in that area - not as prime as this - in excess of $1000 a square metre, plus GST.''
DCC strategy and governance general manager Sandy Graham told the Otago Daily Times the council's media release incorrectly stated the decision was unanimous.
There were no votes against the decision, but the staff who wrote the media release misinterpreted that as being equivalent to a unanimous vote for, Ms Graham said.
