Andrew William Lee, 33, is alleged to have struck Mr Cronin from behind at the Windy Mile hotel in Diamond Creek on the night of April 16.

Mr Cronin, 19, left the hotel with friends afterwards but was taken to hospital the next day and died on April 18.

Mr Lee's lawyer on Thursday questioned the strength of the Crown case during his client's bail application, and said Mr Lee never intended to punch Mr Cronin, and was instead trying to hit the teenager's friend.

"To put it bluntly, this is not a case of murder ... and it never will be murder," defence counsel Mark Gumbleton told Justice Karin Emerton.

CCTV footage played to the court showed an altercation between one of Mr Cronin's friends and two of Mr Lee's friends, and punches exchanged.

As Mr Cronin tried to restrain his friend, Mr Lee threw two punches.

One struck Mr Cronin's friend and the other hit Mr Cronin.

Police have not identified Mr Lee's friends.

Mr Gumbleton said Mr Lee unintentionally punched Mr Cronin when the teenager and his friend as the pair moved.

He said much was unknown about the extent of the injury Mr Cronin suffered, as the punch did not knock him to the floor and he was able to walk home.

The allegation of intending to kill the teenager was a question for a jury, the lawyer said.

A charge of manslaughter was a "different question" to that of murder, he said.

Justice Emerton said there appeared to be a "weakness" in the prosecution case, and that the Crown had to prove Mr Lee showed murderous intent during a brawl.

The brawl involved "tens of men", the court was told earlier.

Prosecutor Peter Rose, QC, labelled Mr Lee's actions "cowardly" and said he had joined a fight he had no involvement in, and given his proficiency in martial arts, had punched a defenceless man with such force to cause a brain injury.

Police opposed Mr Lee's bail application because of the seriousness of the charge and over concerns he would hinder their investigation if released.

Detective Senior Constable Glen Scharper told the court two witnesses had told police Mr Lee's punch appeared deliberately aimed at Mr Cronin's head.

Police had found it difficult to get information from other witnesses, Detective Senior Constable Scharper said, out of "a sense of loyalty or fear from the [Lee] family".

Mr Lee's brother, Brendan, was last month convicted and fined $2000 after pleading guilty to harassing a potential witness.

The court heard on Thursday that  Brendan Lee had spoken with his brother's solicitor, Zarah​ Garde-Wilson, and given her business card to a witness.

The court heard Andrew Lee's parents were prepared to offer a substantial surety. Photo: Eddie Jim

Brendan Lee, the court was told, instructed that man that Ms Garde-Wilson could have his statement retracted.

There was no evidence Ms Garde-Wilson spoke to Andrew Lee about having her business card passed on, the court heard.

Mr Gumbleton said his client would have faced up to 18 months in custody awaiting trial if he had been refused bail.

Mr Lee's parents were, he said, prepared to offer a substantial surety.