Death was from the fall, not the punch.
Mr Cassai fell straight backwards, hitting his head on the pavement and fracturing his skull. He died of his injuries at The Alfred hospital about 4pm on December 31.
More difficult to find the cause of death. Nothing to say it was the punch.
Justice Fullerton said after Mr Kane fell to the ground Field left the pub without checking on him and has never shown remorse for his actions.
Again the facts aren't stated in the article you are quoting. Nothing in the article giving the cause of death.
Extensive bleeding of the brain could be as a result of a punch but is far more likely to be from the head striking the ground.It is alleged Garth punched Mr Manalad once to the head shortly after 1am on Saturday, causing him to fall onto the concrete, after the 21-year-old nursing graduate tried to intervene during a fight between his accused attacker and his girlfriend at a party in Minchinbury.
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Mr Manalad, who was also 21, suffered extensive bleeding on the brain and died in Westmead Hospital the next day.
However his solicitor made a claim that means that you might have difficulty with case law because even his solicitor said there is none.
Garth's lawyer, Riyad El-Choufani, told the court Garth should be granted bail because he needed full access to his legal team to build a defence to the charges, which are new and have no legal precedent.
If anyone gets into a fight and one party falls to the ground hitting his head it is likely that the assailant will go to jail. But nothing here supports your claim of case law proving that one punch kills. The case law is that if you get in a fight and someone dies you will go to jail unless you are the innocent party. I can guarantee the likelihood of that too.
My 'guarantee' is if you gouge someone's eye you will go to jail and I gave you three examples where the courts sent people to jail for gouging eyes.
Perhaps you need to rethink your evidence!then there is enough case law to guarantee a punch kills you. You may want to re think your evidence there.