Brady Phillip Sheather, 22, is charged with the manslaughter, by an unlawful and dangerous act, of Phillip Sheather, 56, at their Bungendore home on February 23.

His mother and the dead man's widow, Megan Sheather, has previously been granted bail on a charge of being an accessory after the fact of manslaughter.

The Crown alleges father and son were alone at home when Sheather struck his father causing him to fall and hit his head.

In the NSW Supreme Court on Monday, the prosecutor cited a recording when the son said he had "tapped" his father on the head, contending this was "an important admission of contact with his head".

In arguing for bail, Sheather's barrister Tony Evers said it was not clear what the son meant by a "tap on the head" and whether it was of sufficient force to create a risk a reasonable person would appreciate would cause serious injury.

In the recording, Sheather referred to the tap after replying "no" to his sister's question about whether their father fell after a push.

Mr Evers described the father as "an aggressive, difficult man when drinking" and said he drank 36 bottles of beer in the 24 hours leading up to his death.

In granting bail, Justice Robertson Wright said the crown case was not "overwhelmingly strong" but it also was not weak.

"It appears the deceased, the applicant's father, had been drinking a very significant amount of alcohol, perhaps of the order of 36 bottles of beer," he said.

His son had been lying on the sofa, and allegedly woke up and saw his father near the TV.

He then allegedly struck him on the side of his face at least once, leading him to fall backwards and suffer the head injury which led to his death in hospital days later.

When his mother arrived home and later called emergency services, she said her husband had fallen over after "my son and him were being stupid".

The judge noted Sheather had no history of violence, his only conviction was for stealing cattle, he had "an extraordinary level of community support" and a job to go to.

His GP and a psychologist raised concerns about his vulnerability in jail, noting mental health issues.

Justice Wright imposed bail conditions which included Sheather living with his aunt and grandfather, who will deposit $10,000 surety, report daily to Queanbeyan police and be subject to a curfew from 7pm to 6am.

He is not to have any communication, except through lawyers, with his mother or his sister.

Mother and son are due back in Queanbeyan Local Court on November 5.

Australian Associated Press