About 10 officers were waiting for Jesse Noakes, 36, Gerard Mazza, 33, and Matilda Lane-Rose, 20 when they arrived at Woodside chief executive Meg O'Neill's Perth home in August 2023.
They, along with Emil Davey, 23, were initially facing a charge of conspiracy to commit criminal damage but that was downgraded and they pleaded guilty to attempted unlawful damage and trespass.
Outside Perth Magistrates Court on Tuesday following sentencing submissions, Mr Davey said the Disrupt Burrup Hub members' actions were justified.
"We've seen wildfires all across the country and in (California) recently, people's homes are being burnt down," he told reporters.
"We know that the fossil fuel industry is making this (climate) crisis happen, so the line is certainly already being crossed and we're just trying to do something about it."
Mr Davey agreed he had broken the law but said his actions were those of "any morally upstanding citizen" and "I'm not sorry to Ms O'Neill".
"If other people want to pursue the (chief executives) of fossil fuel companies, I think they need to be held accountable," he said.
Inside court, Chief Magistrate Steven Heath asked the lawyers representing the group whether they had crossed a boundary of acceptable protest behaviour by going to Ms O'Neill's home.
Woodside CEO Meg O'Neil said the group's action was designed to threaten her and her family. (Aaron Bunch/AAP PHOTOS)
It was largely accepted they had but the lawyers also pointed out the group had not entered the property or damaged it because they were arrested as soon as they arrived.
"This was a publicity stunt to gain attention for their cause," Mr Noakes' lawyer Nick Terry said.
Police had been aware of the group's plans for about a week before their early morning arrival at Ms O'Neill's home with an ABC Four Corner television crew, who had intended to film the action.
The court was told Mr Davey had been stopped by police as he drove past the home in his Toyota Hilux the night before the incident.
"A car pulled in front and two men got out of the car. It was an unmarked police car. One of the men pointed a gun in Mr Davey's face. This man was dressed in black ... with no visible accoutrements of being a police officer," Mr Davey's lawyer Anthony Elliott said.
In the days after the incident, Western Australian Premier Roger Cook said the action was carried out by "extremists seeking to terrorise".
Ms O'Neill also said the group were extremists and the action was designed to threaten her and her family.
The court was told the group had paint, water balloons and a bicycle lock with them when arrested.
Protesters claim Woodside could produce billions of tonnes of CO2 by 2070 from the Burrup Peninsula. (Aaron Bunch/AAP PHOTOS)
Mr Cook also wrote to the ABC to complain about the broadcaster's alleged "complicity" in the incident.
The Burrup Peninsula, in WA's northwest, known as Murujuga to traditional owners, contains the world's largest and oldest collection of petroglyphs.
Disrupt Burrup Hub claims Woodside's operations in the area and its proposed expansion could produce billions of tonnes of carbon dioxide by 2070.
It has carried out a series of actions against Woodside in recent years including the release of stench gas at the company's Perth headquarters which forced the evacuation of about 2000 staff.
The group will be sentenced later in the month, with the lawyers suggesting a fine was the appropriate punishment for their clients, and that Mr Davey and Ms Lane-Rose should be given spent convictions.
The police prosecutor disagreed, saying it was a serious offence and not a trivial matter and the group were not remorseful.
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