Mr Barker told Coroner Scott his family were associated with the Mongrel Mob, although he was not in a gang, and Mr Zurich was a supporter of Black Power. He had been involved in a fight with Mr Zurich before the incident and he felt they might blame him for fuelling Yusef's anger.
Mr Toy said police investigations found Mr Zurich had been drinking with friends and family at the Bedford St address from about midday on the day he died.
Most were drinking 8 per cent alcohol Cody's and were heavily intoxicated, including Mr Zurich. Police were called to the house at 9.25pm for what was believed to be an altercation but none of the partygoers would speak to police, so they left again.
At 11.40pm, a physical altercation began between Mr Zurich and Nassa, and it was established they often fought when drinking together.
Mr Barker was outside when the fight started and, on hearing them argue, made his way inside with two associates. A fight started between the three men, Mr Zurich and his brother Poitrel.
To get away, Mr Zurich and Poitrel went upstairs to a bedroom, while the other men were on the stairwell.
In his anger, Mr Zurich punched the window in the room, then went back downstairs and fell to the floor before losing consciousness. He was taken to hospital but died shortly after.
A post mortem found he had a blood alcohol level of 295mg per 100ml of blood. The blood alcohol limit for driving is 80mg. Cannabis was also detected.
His death was initially treated as a homicide, when some witnesses said they heard the words: "You've killed him."
However, it was established that there were Mongrel Mob and Black Power affiliations at the party and the inferences were made in the heat of the moment.
It was also established that Mr Zurich had punched a window in a similar manner with his left arm in the months prior to the incident, causing nerve damage.
Both Mr Zurich's siblings described seeing a lot of blood.
Poitrel, who was in the room when the incident occurred, recalled Mr Zurich punching the window with his right arm, not his injured one. "Yusef was drunk. He is one of those lash-out people."
He hit the window because he was "bummed" they had been "smacked over" by Mr Barker and his friends downstairs.
"Blood was pouring out. I was shocked at what I was looking at. Blood was everywhere."
Rebekah said in one of her statements that she sat with Yusef's head between her knees.
"Yusef was bleeding badly, it was like a tap had been turned on, my knees were in a large pool of blood."
Coroner Scott said he would make a decision on Tuesday but indicated that he would be outlining the nature of the party, the amount of alcohol consumed and the fighting there, the incident itself, and the actions of partygoers and neighbours in getting Mr Zurich to the hospital.