The Australian Federal Police say the "technical" legal breaches involved in its raid of the construction union's Dickson headquarters are not serious enough to withhold evidence of potential criminality.
The Construction, Forestry, Mining, and Energy Union on Tuesday continued its push to have vast volumes of information and documents seized by the AFP in August either returned, destroyed, or invalidated.
The raid lasted 13 hours, requiring a second warrant to be obtained, and saw roughly 10,000 documents taken by police attached to the AFP's trade union royal commission taskforce.
The union has alleged the raid was illegal on a number of grounds, including that its members were restricted from observing police, that there was no evidence to support the issuing of a second warrant, and that copies of the seized material were not given to CFMEU officials as required.
But the AFP's barrister, Andrew Berger, used his closing submission to the ACT Supreme Court on Tuesday to describe the breaches as "technical".
He said they were not serious enough to justify the withholding of evidence potentially showing serious crimes.
"We submit all of the breaches comfortably fall into the category of technical ones," Mr Berger said.
The CFMEU, however, is alleging some of failings during the raid were much more serious.
On Tuesday, the union's barrister, Peter Morrissey, SC, used his closing submission to accuse police of deliberately planning to restrict the movement of union officials during the first hour of the raid.
He said the right of an occupier to observe police as they executed a search warrant was "absolute".
"It is an absolute right. It's a right to observe ... It can't be taken away by a decision of the police," he said.
A number of police officers gave evidence on Tuesday that the restrictions were designed to protect police methodology, or ensure safety due to the presence of the bomb squad.
Mr Morrissey questioned the head of the operation, Sergeant Scott Utteridge, about why the bomb squad posed such a safety hazard.
Sergeant Utteridge said measures were taken to protect their use of sensitive equipment and limit the risk it posed to others, including possible dangers of radiation.
He said the bomb squad had asked for an exclusion zone.
But Mr Morrissey said CCTV footage showed they only took a ladder, mobile phones, goggles, coffee, and McDonalds on site.
He asked Sergeant Utteridge: "Is this truthful evidence?"
The officer replied: "Yes, it is."
Mr Morrissey later submitted that the safety rationale justifying the restriction of union officials appeared to have emerged late in court proceedings, something he described as concerning.
The union's civil case also complains of the police's failure to make copies of the seized documents for the CFMEU, something that allows for an occupier to see what has been seized and seek appropriate legal advice.
Police said it wasn't feasible to make copies at the time, given the small number of officers and quantity of material involved.
Sergeant Utteridge said he had always told CFMEU officials they would receive the copies shortly, and spoke of the complications he faced in obtaining adequate resources for the raid.
He said he asked for help from ACT Policing's crime manager before the raid, but only two to three officers were available.
Sergeant Utteridge said he then approached his old patrol team in Woden, and was given several officers.
He said he thought that would be enough resourcing, but it became clear during the operation that it wasn't adequate.
Mr Morrissey asked why he hadn't called for more manpower.
The officer responded that he did not make the request because he already knew what the answer would be.
The hearing continues before Acting Chief Justice Richard Refshauge.