A “hot mic” had recorded what was supposed to be a private conversation between the three members of the board when they were discussing the convicted sex offender's release.

When the comments were later transcribed they showed one member, Janine Bromwich, had described the man as a "back of the neck hair boy". The associate justice hearing the man's review took that as a reference to the man being someone that made her shudder or fearful.

Mr Moss said there would be "no point" hearing from the man's mother on the question of his parole.

The third member Don Malcolmson expressed concern that if they did not hear from the man's mother there might later be a question of procedural fairness.

Their conversation formed the basis of Associate Justice Verity McWilliam's findings last week that the board as a whole was affected both by bias and apprehended bias.

The board is a government-appointed body that makes important decisions on people’s liberty, such as whether an inmate should be released on parole. There are limited options for a person to review its decisions.

It met three times to consider the man's parole, and refused his request each time, though the man was eventually released when his sentence expired.

The man, who was jailed for using, possessing and producing child pornography, had been seeking release on parole to live at his mother’s home.

However, included in a pre-release report was an assessment that the home was unsuitable given its proximity to a school and scout hall.

In the first hearing, the same report incorrectly said he was a medium to high risk of reoffending when he had in fact been assessed as a low risk.

Associate Justice McWilliam found that in the board's first decision the error caused the entire process to miscarry, given the significance of a risk assessment when considering the suitability of an address.

At the second hearing, the man asked the board to let his mother, who had come to the hearing from her sick bed, answer their questions about the location and environment of her house.

He was arguing his request before the board when it adjourned to consider it, with Mr Moss - a former integrity commissioner, a member of the ACT Electoral Commission and the man who led the review into the death in custody of Steven Freeman - saying he could not see the point of hearing from the man's mother.

The microphones were not turned off during the adjournment and recorded the private conversation that followed between Mr Moss, Ms Bromwich and Mr Malcolmson.

The comments were later transcribed and showed the board had prejudged the parole decision, Associate Justice McWilliam found.

She noted Ms Bromwich's comments about the "back of the neck hair" - whatever their meaning - were not complimentary and were disrespectful of an applicant for parole.

Mr Moss had concluded there was "no point" hearing anything further and the board heard from the mother "only as a courtesy" rather than actively listening to relevant evidence, the associate justice found.

Because the man had already served his sentence by the time his review was heard in the ACT Supreme Court he sought declaratory relief - which confirms a person's rights and guides future decision making.

In a lengthy and detailed judgement the associate justice ordered declaratory relief for both the first and second decisions for the reasons above, but found the third valid.

She ordered the director general of the justice and community safety directorate pay the man’s costs.