Justice Soraya Ryan has retired to consider a verdict in the judge-only Brisbane Supreme Court trial but warned on Wednesday that it would take at least a month.

"I have just got another month or so to wait. It's a shame but that's what we have got to do," Jack's father Brett Beasley said.

"It's been two-and-a-half years now. We have to wait another 28 days minimum - it's terrible.

"It's been a pretty hard week and a half as it is, so it's going to be even worse now."

Five boys - aged between 15 and 18 at the time - were arrested following Jack's death in December 2019.

Three teens pleaded not guilty to manslaughter and two counts of grievous bodily harm.

Jack was stabbed in the heart during the fight between his group and five teens at Surfers Paradise, the court was told.

Jack's parents left the court every time CCTV footage of the 29-second fight and its aftermath was shown throughout the trial for the three teens.

"It's heartbreaking. We can't stay there watching it," Mr Beasley said.

After spotting Jack's group at Cavill Mall, five teenagers ran two blocks in pursuit before starting a fight with them, the court heard.

A 15-year-old had a knife tucked in his pants, stabbing Jack once, piercing his heart, and another 17-year-old boy twice - puncturing his lung.

The five teenagers discussed robbing someone for drugs and then planned to assault Jack's group, giving them "no option but to engage" in a fight, crown prosecutor Todd Fuller said.

He said CCTV footage did not support a claim that Jack's group had challenged the five teens to "come have a brawl" when they first spotted each other at Cavill Mall.

However, defence barrister Gregory McGuire - who told the court he did not want to "victim blame" - said Jack "reacts provocatively" to one of the five teens before the fight started.

CCTV footage showed Jack throw a cigarette into a teen's face after being pushed and then shaping up before the fight erupted.

"Clearly he (Jack) was not backing down. He was more than happy to take the other group on," Mr McGuire said.

The three defence barristers also rejected Mr Fuller's argument that death or grievous bodily harm could be a "probable consequence" of a fist fight.

"The fight was seemingly caused by an excess of testosterone and stupidity," defence barrister Catherine Morgan said.

"Sadly ... this is a situation that is quite common in pubs, sporting events, in the school ground and ... it doesn't usually end in death and grievous bodily harm."

She also played down CCTV footage showing her client fist bump another teen as they ran away from the fight, saying it may not necessarily mean "well done".

A teenager - who was 15 at the time of the incident - this month pleaded guilty to murder and two counts of committing malicious acts with intent.

Another teenager - who was 17 at the time - pleaded guilty to manslaughter and two counts of grievous bodily harm in April.

Meanwhile, Mr Beasley said his son's legacy would live on through the Jack Beasley Foundation which aims to curb youth violence.

"Kids need to be educated of the repercussions of carrying a knife," he said.

"We don't want any parents to be standing where I am today."

Australian Associated Press