Prosecutors and the defence described the offence committed by Captain Rhiley Boyson against his friend as a prank, “an act of tomfoolery gone too far".

After a five-day court martial, and an hour and a half of deliberating, a panel of five male officers found 26-year-old Boyson guilty of one count of sexual intercourse without consent earlier this week.

On Tuesday, the panel retired to consider the sentence they will impose and it is expected they will deliver it on Wednesday.

It seemed likely Boyson will be kicked out of the army, either by the panel ordering a sentence of dismissal or through an administrative termination notice after the conviction, the court heard.

The man’s liberty also hangs in the balance, as a sentence of imprisonment is one of the punishments available to the panel.

Any sentence to be imposed on Boyson must be voted on by the panel, and receive a majority of votes. The same applies to the verdict.

Tuesday’s hearing at the court martial facility in Fyshwick was told Boyson had been at an army social function in 2017 with the victim, who was a friend and fellow officer.

The group's drunken bathroom horseplay ended with the victim in a vulnerable position on the floor frantically trying to pull his pants and underwear up.

Boyson inserted a beer bottle into the man’s buttocks in an incident that lasted a few seconds.

The victim did not report the incident to Defence Force police until later that year.

Boyson was suspended without pay while he awaited last week’s court martial.

He pleaded not guilty, but another officer gave evidence that the victim had told her what happened soon after, and that Boyson later admitted it to her.

The prosecution was launched in the military jurisdiction with the consent of the relevant state Director of Public Prosecutions.

That consent must be obtained before a military prosecution when it comes to certain offences, including rape and murder.

On Tuesday, prosecuting officer Squadron Leader Sarah Robin told the panel the offence was a prank gone too far.

She said low-brow humour at the urinal had escalated out of control.

"[It was] intended as a prank that simply went too far at the expense of the victim," she said.

She read to the court a victim impact statement from the officer, who reported severe anxiety and difficulty interacting with his family since the incident.

He had missed out on a dream job posting after being medically downgraded, and was slowly returning to Defence Force social functions where he once felt he was safe.

As a prank or otherwise, the officer’s behaviour was completely unacceptable, Ms Robin said. She said Boyson has not shown remorse nor apologised to the victim.

Boyson's defence officer, Flight Lieutenant Sophie Callan, called the incident a moment of madness that would have lifelong consequences.

”You would conclude this was very much an aberration,” she said.

It was "an act of tomfoolery that went too far".

The offence was opportunistic and not premeditated, there was no malice involved nor sexual gratification, nor was there violence involved, she said. Boyson had an impeccable service record and no criminal convictions in his past.

One of the man's senior officers told the court Boyson had impressed him with his dedication and work ethic.

Ms Callan said Boyson had joined the army at 17, and flying was the officer’s life.

The defence officer said the consequences of a conviction would extend beyond any imposed by the panel, including damage to his reputation.

She told the court that for Boyson to continue his career as a pilot in civilian life would take six months and cost more than $100,000, likely beyond the man’s reach given his poor financial situation.

Ms Callan suggested the panel consider dismissing Boyson from the army but stop short of imposing a sentence of imprisonment.

Chief Judge Advocate Michael Cowen QC gave the panel directions on the law around sentencing before he sent them out to consider the punishment.

They will return on Wednesday to continue deliberating.