A rule used to controversially cut short debate in a council meeting this week was used incorrectly.
The council says the decision made is still valid, in spite of the procedural blunder, but a local government law expert says the situation may present a legal risk if challenged.
On Tuesday three councillors walked out of a meeting and one refused to vote after Deputy mayor Larry Baldock called a procedural motion to end the debate before all elected members had an opportunity to speak.
His motion was seconded by Councillor Kelvin Clout.
Mayor Tenby Powell called the vote on the agenda item - an $11m transformation of an Elizabeth St block - immediately after. It passed 6-4 with Councillor John Robson refusing to vote in protest and councillor Steve Morris calling the situation a "Baldocracy".
Councillors Morris, Andrew Hollis and Dawn Kiddie then walked out of the meeting, which was being held via live-streamed video conferencing and had been going on for about five hours.
The trio later said in their view the council leadership pair robbed them of their right to express their views.
Clout has apologised for his role but Powell and Baldock defended the move , saying the democratic process was upheld and the walk-out was immature.
According to the rule Baldock cited, however, closing the debate needed majority support and should have been put to a vote before the Elizabeth St vote could be taken.
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The error was identified by Councillor John Robson after the meeting, and council staff confirmed it after inquiries from the Bay of Plenty Times.
Susan Jamieson, general manager of people and engagement, said the fact the procedural motion was not put correctly did not invalidate the Elizabeth St decision. All councillors had the opportunity to vote.
She blamed technical issues for the reason no staff members intervened.
"Staff attempted to provide verbal advice about the process, but could not be heard because of technical problems. The vote had already taken place by the time contact was made by text message.
"This highlights the challenges of conducting a virtual meeting."
The rule in question is one of the council's standing orders, which were updated at the start of this council term.
Dr Dean Knight, associate professor at Victoria University's Faculty of Law and New Zealand Centre for Public Law, said standing orders are "the important rulebook governing local government meetings.
"They must be complied with under the Local Government Act unless 75 per cent of members present vote to suspend them temporarily.
"A decision taken contrary to standing orders could, if tested in court or investigated by the Ombudsman, be ruled invalid. However, while compliance is important, the courts would also probably take into account the gravity and context of any breach too.
"It would be wise for the council to look closely at what has happened in the light of this legal risk," he said.
Powell said any council decision could be subject to a judicial review but in this case, the risk of it being overturned was minimal, in the council's view.
"Given the current economic climate and the significant cost of a judicial review, such action would seem somewhat misguided."
Asked for comment on the error, Baldock at first said Powell had put his motion to a vote, but later acknowledged that did not happen.
He said the Elizabeth St vote stood.
He also provided his own definition of the term Morris coined, "Baldocracy": "A new improved democracy with less time wasted on political stunts, endless irrelevant questions and BS."
Morris, who was the first to walk out, said he would let Baldock define the usage of his own name, but said in response to the definition: "If the mayor and councillors aren't prepared to listen to each other's differing views, what hope is there they will listen to the public when they have a contrary view."
He agreed the Elizabeth St vote stood, but believed a majority of councillors would not have supported cutting the debate short, had they been asked to vote, and the incident caused confusion.
Hollis said he was seeking legal advice on the incident and would decide whether to take it further once that was received.
Video of the meeting, which went for six hours in total, has been viewed nearly 700 times according to the council's Youtube channel. Council meeting videos typically get fewer than 100 views.