Jack was aged 17 when he died after being stabbed in the back and chest in December 2019 after a fight broke out between his group and five other teens at Surfers Paradise.
Jack's father Brett Beasley raised his arms and shouted in triumph as he exited Brisbane Court of Appeal accompanied by family members and police on Friday morning.
The court's three justices had taken just a few minutes to reach a decision to end the appeal at an early stage.
"That didn't take long, did it? It had to be a no-brainer," Brett Beasley said outside court.
"He got what he deserved, as far as we are concerned. He got it squashed. I'm a bit speechless."
Mr Beasley said it had been devastating to have to return to court and listen to the details of his son's murder being discussed again.
"It's always hard to hear but we got the result today and that's what we were hoping for," he said.
Two teenagers were jailed over the incident that led to Jack's stabbing.
One of the boys, aged 15 at the time, was sentenced to 10 years imprisonment after pleading guilty to murder and committing malicious acts.
The appellant, who cannot be named for legal reasons, was ordered to serve 70 per cent of the sentence, which is seven years.
His barrister Andrew Hoare had sought to reduce the teen's sentence to five years, which could have seen him released by his 21st birthday.
Mr Hoare told the court the trial judge was incorrect in finding no special circumstances to reduce his client's sentence.
Mr Hoare said in addition to pleading guilty, his client had also surrendered to police after CCTV of the incident was released to the public.
"The accumulation of those matters ought to have led to a finding of special circumstances," Mr Hoare said.
"He had no prior criminal history and no sign of resistance to rehabilitation.
"His statement made in open court ... had genuine remorse."
Prosecutor Sarah Dennis said the appellant committed extremely serious offences and delivered what the trial judge described as a "coward blow" by stabbing Jack from behind.
"A review of Her Honour's remarks cannot support the conclusion that a failure to find special circumstances was unreasonable and unjust," Ms Dennis said.
The appeal justices ordered that the leave to appeal application would be refused with reasons to be published at a later date.
In March, the Queensland parliament passed Jack's Law to extend the police's trial use of handheld metal detectors to scan people for weapons in night club precincts.
Six knives were detected and seized from 586 scans across four days earlier this month.
Speaking outside court, Jack's mother Belinda said the law could not save her son's life but could save someone else's.
"There are lots of kids out there that have lost their lives to knife crime so if we play our little part, and it's in Jack's name, that's a real honour to him," she said.
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