Supporters of Jack's family clashed with a rival group in Brisbane Supreme Court after the two boys received their prison sentences.
"Your son is a f***ing murderer," a supporter screamed.
Security stepped in to ensure the two groups left the building separately, with Jack's devastated family opting not to speak with media gathered outside.
Emotions ran high after one boy who was just 15 when he stabbed Jack in 2019 received a 10-year jail sentence for murder and other charges, and the other - who was 17 - a seven-year term for charges including manslaughter.
The two boys earlier received stern words from Jack's mother Belinda Beasley who read a tear-filled victim impact statement on Friday.
"You have taken away Jack's life and ruined so many others with the choices that you made that night - and for what?" she said.
"You ran away like cowards and left Jack ... to die on the footpath without a care in the world - what sort of people are you?"
The two boys were among five teenagers - aged between 15 and 18 at the time - who were charged after Jack was killed in December 2019.
Jack was stabbed in the heart and later died in hospital after a fight broke out between his group and the five teens in Surfers Paradise.
Ms Beasley said her family had endured a "living nightmare" ever since.
She said the sight of Jack's lifeless body at the hospital will "haunt us for the rest of our lives" and the sound of an ambulance siren sparked flashbacks of the night she lost her "beautiful boy".
"We will never be the same. You didn't just kill Jack that day, you killed our entire family - the pain never goes away."
Ms Beasley said being a juvenile was no excuse for their "unforgivable" actions.
Justice Soraya Ryan said she hoped the boys "carry (Jack's) mother's words with you for the rest of your life", describing the fatal stabbing as "profoundly tragic and utterly incomprehensible".
The boy who stabbed Jack - who is now 17 - tendered a written apology that was read in court before briefly standing up to say he was "very, very sorry".
"There are no words ... that are going to take away any pain that I have caused," the letter read.
"I understand that I may never be forgiven but I hope one day I will. I am sorry from the bottom of my heart."
They boy admitted he had stabbed Jack in the chest and another 17-year-old boy twice during the fight, pleading guilty to murder and two counts of committing malicious acts with intent.
He must serve 70 per cent of the 10-year sentence.
The other boy - who is now 20 - pleaded guilty to manslaughter and two counts of grievous bodily harm.
On Friday he also pleaded guilty to three other charges including robbery and assault offences that occurred in July 2019 and August 2020.
He must serve 50 per cent of his seven-year term.
The teen has been in custody for two-and-a-half years - considered time served - and is eligible for parole in 12 months' time.
Ma-Mal-J Toala - aged 18 at the time - and two teenage boys who can't be named were each found not guilty of manslaughter and two counts of grievous bodily harm after a judge-only Supreme Court trial this year.
9°C