Magistrate Geraldine Beattie told Goulburn Local Court on Wednesday, April 10, that 19-year-old Cody Benn's physical attack on a 70-year-old man was "totally unwarranted and shameful."

Benn, of Goulburn, pleaded guilty to one count each of common assault; behaving in an offensive manner in or near a public place; and intentionally destroy/damage property less than or equal to $2000. The latter related to a separate, earlier matter, the court heard.

Magistrate Beattie said on the night of November 9, 2023, Benn, then aged 18, and a younger female boarded a Sydney bound train at Goulburn and entered a quiet carriage. They became loud and continued this when asked to move into another carriage.

The court heard there was a verbal encounter between the elderly man and the younger female, which escalated. The female started videoing on her phone. Benn's solicitor, Ben Carpentier, said Benn had told the man: "Touch my f--king sister, you dog." Mr Carpentier said the person was not in fact Benn's sister.

Further, Benn had threatened to "end the man's life".

Magistrate Beattie said there was no evidence of the elderly man's contact with the girl but at this point, Benn pushed the 70-year-old forward in his chair and punched him to the head.

"It didn't end there. You take away his walking cane and use it to to hit his body multiple times," Magistrate Beattie said.

"At no time do you stop, despite him not being in a position to fight back. You attacked an incredibly vulnerable person who was helpless to what you were inflicting on him and you kept threatening him."

Magistrate Beattie said when the victim stood, Benn had pushed him back in his chair. When the man tried to defend himself with his cane, Benn had kicked him "multiple times".

"It is totally unwarranted, shameful behaviour," she said.

Earlier, she told the court that the man had been sitting in his seat "not causing any problem to (Benn)" when the accused spoke to him.

Magistrate Beattie said the encounter was later uploaded on social media.

Mr Carpentier said the victim was an "elderly homeless man".

"It would have been a terrifying situation for him," he told the court.

Mr Carpentier said a sentence assessment report highlighted Benn's "lack of insight, born of immaturity".

The court heard that in September 2023, on the back of a "prior dispute," Benn attended a Goulburn home with two other people. Benn had smashed the windscreen of the victims' car and damaged the driver's side door. He was subsequently charged with destroying property.

"He needs to learn other ways to deal with such situations and not fight. He admits he has anger management problems and that he deals with his anger through violence," Mr Carpentier said.

But he argued that Benn was "still young enough to do some growing up" and asked the magistrate to impose community correction orders.

Magistrate Beattie said it was "about time (Benn) started doing something about his anger management".

"When I read your sentence assessment report I'm very concerned because there is no reflection on what you've done or any feeling for the victim," she said.

The magistrate said nothing justified Benn's actions but she accepted that his brain had "a lot of growing up to do" and he had to develop empathy.

On the common assault charge she imposed an 18-month community corrections order and 180 hours community service. Magistrate Beattie fined Benn $450 for behaving in an offensive manner near a public place and imposed a 12-month community corrections order for destroying/damaging property.