The lawyer for one of the men accused of murdering a Wellington journalist says that if his client is found not guilty of murder, there is no doubt he is guilty of manslaughter.

But Nicho Waipuka was not offered the chance to plead guilty to manslaughter.

Had he been, he would have pleaded guilty, his lawyer said.

Manuel Robinson, 18, and Waipuka, 20, have been on trial in the High Court at Wellington charged with Phillip Cottrell's murder.

Paul Paino, representing Waipuka, told the jury in his closing argument yesterday that his client was not able to plead to a manslaughter charge because it was not offered.

"There's no doubt that if he's not guilty of murder, he's guilty of manslaughter."

In his opening statement to the jury, Mr Paino said Waipuka accepted he punched Mr Cottrell in the jaw once.

He acknowledged that his client was in a "troublesome" mood that night.

"Waipuka punched a man and then ran up the road and told people ... and thought it was a bit of a joke."

He implored the jury to look at Waipuka's maturity when deciding whether he had murderous intent.

"There's a general theme of immaturity running through [both] the accused."

Mr Paino said Waipuka made a "simple straight punch at head height".

"There were not three kicks, the defence's case is that there were no kicks but it was added on by the accused [when talking to friends and family]."

Waipuka added on statements about kicks because he was showing off and getting carried away. "[He is] an immature man with a warped sense of humour," said Mr Paino.

After two weeks of Crown evidence, lawyers for Waipuka and Robinson did not call any witnesses to give evidence.

Mr Cottrell was rushed to hospital after being left with broken bones and a shattered skull in an attack on a central Wellington footpath early on December 10 last year. He died in hospital the following day.

In the Crown's closing argument, prosecutor Grant Burston told the jury that Waipuka and Robinson did not need to have inflicted the fatal blow to have been party to the murder.

"The Crown says both accused were involved in the beating ... whoever it was who inflicted the fatal blow."

The evidence, when considered together, meant both were involved in inflicting blows that contributed to Mr Cottrell's death, he explained.

Mr Burston said the attack was completely unprovoked, leaving Mr Cottrell's head and body broken.

Both accused were aggressive to others before the attack, and both admitted being involved in the attack on Mr Cottrell.

"The Crown says that what the two accused did to Mr Cottrell is murder. You may feel sorry for one or both of the accused ... you may feel pity for Mr Robinson that he has club feet and didn't do well at school.

"However, feelings of emotion ... have no place in a murder trial," Mr Burston said.

The defence's closing arguments are continuing.