Near Sydney's Star casino a drunken group bickered and begged for money before Graham Anthony Egan smashed a whiskey bottle and fatally stabbed his friend.
The 53-year-old was sentenced in the NSW Supreme Court on Friday to a maximum term of seven years and six months, and a non-parole period of five years.
In December he was found not guilty of murder but guilty of manslaughter by a jury for killing Benjamin Coleman, 40, opposite Pyrmont Bay Park on September 22, 2019.
Justice Richard Button said the evidence at trial painted a poignant picture of the happiness and conviviality of the passers-by heading to the casino, and the futility and underlying despair of those occupying the footpath.
Both men along with another friend and Mr Coleman's partner had spent hours drinking and collecting donations from pedestrians near the local Coles.
The group who had all suffered a great deal of deprivation and hardship were well intoxicated according to CCTV footage played in evidence, the court was told.
The video footage also showed the friends drunken crotchety bickering that developed into pushing and shoving was immediately resolved with handshakes and reconciliatory hugs.
But in the early hours of the morning Egan smashed the liquor bottle on a concrete pillar and advanced towards Mr Coleman who moved back and threw some punches before both men fell to the ground.
Coincidentally a woman nearby began filming herself and the 17-second selfie tape ended up in evidence depicting the sound of the cracking bottle and the two men's movements.
Tragically in the struggle Egan pushed the sharp neck of the bottle into Mr Coleman's throat resulting in a deep wound and his death later in hospital.
Egan promptly walked away but was arrested nearby, telling police "I know what I done".
The jury's verdict established that Egan did not inflict the wound with intent to cause death or serious injury.
Mr Coleman's sister Belinda described her brother as protective and reflective in nature and that his sleeping rough had been heartbreaking for the family.
Shortly before his death he had found suitable accommodation "and it seemed things at last might improve," the court was told.
"The loss of this much-loved man was a crushing blow for his family both as individuals and as a whole."
Egan grew up with only one Aboriginal parent present who was the victim of an historical injustice, the court was told.
This led to their powerful dependence on alcohol, and created a violent and abusive childhood for Egan whose education was grossly disrupted.
Egan's alcohol and drug use as a teenager led to his homelessness in early adulthood, and he was stabbed while living on the streets in 2017.
He has been diagnosed with several mental health conditions including PTSD and has been imprisoned ten times before, once for intimidating a person with a broken bottle.
The similarity of this offence "is obvious, and obviously troubling," Justice Button said.
The judge found his prospects of rehabilitation were guarded but found he had grudgingly and gradually felt regret that extended beyond concern merely for himself.
