Close friend Christopher "Kip" Davey told the Supreme Court on Friday that Mr Hardy could be argumentative and irrational after having too much to drink but he had never seen him get involved in any physical violence.

Mr Davey said that the last time he saw Mr Hardy, 21, a third-year arts student who lived at the University of Melbourne's Trinity College, was when he helped put him in a taxi in St Kilda after a night out and told the taxi driver to take him home.

Another friend described Mr Hardy as a "very friendly, outgoing, gregarious sort of guy".

On the way home, Mr Hardy told the taxi driver to let him out on Queens Road before he made his way to the McDonald's on St Kilda Road where he was allegedly set upon by Kyle Zandipour just after 1am on Saturday, October 18, 2014.

Crown prosecutor Andrew Tinney, SC, told the jury Mr Hardy had a blood alcohol level of 0.27 when he came across Mr Zandipour and his friend, Matthew Bell, sitting at an outside table eating their food.

Mr Tinney said Mr Zandipour grabbed Mr Hardy, forcibly slung him to the ground in what appeared to be head first, repeatedly kicked him to the head and stomped on him in an attack which lasted just six seconds.

Mr Hardy was later rushed to The Alfred hospital but died within the hour from head injuries.

Joshua Hardy with his sister Rebecca on their way to a university function only hours before he died. Photo: Shaun Hardy

Mr Zandipour, 29, who has pleaded not guilty to murder, later told police he felt intimidated by Mr Hardy after noticing him at a nearby table looking at them.

He claimed Mr Hardy at one stage walked away, bumped into trees and tried to enter a closed building before coming back and sitting down and staring at them again.

Mr Zandipour said he and Mr Bell talked to Mr Hardy but the arts student spoke in an aggressive tone and tripped Mr Bell as they were leaving and asked for his mobile phone.

Mr Zandipour claimed Mr Hardy became louder and louder when asking for the phone.

"I got really nervous," Mr Zandipour told police. "I grabbed him [Mr Hardy] by the arm, I swung him around because he was fairly tall, so I just put him onto the floor and, you know, I just started to panic.

Joshua Hardy died after being violently thrown to the ground, repeatedly kicked in the head and stomped on outside a McDonald's.

"So he came back up so I thought, you know, something's going to happen. So I kicked him to go down and once he was down I, we walked away, quickly moved away so we had some time to leave".

Mr Zandipour claimed he was scared because of Mr Hardy's body language, the way he was staring, his aggressive tone of voice, how he towered over them and would not answer any of their questions.

He told police he thought Mr Hardy could have been on drugs and it was a tense situation.

"I didn't intend to hurt him, I didn't go out looking for trouble or anything like that," Mr Zandipour said.

But Mr Tinney said Mr Bell would give evidence that there was nothing intimidating or aggressive about Mr Hardy's conduct and he was simply asking to use his phone.

"He [Mr Hardy] didn't say anything and he didn't do anything that could have raised any fear, reasonable or otherwise, in the mind of the accused that Joshua Hardy was going to attack anyone," the prosecutor said.

"Once Mr Hardy was on the ground he presented absolutely no threat of any sort to anyone.  And while he was helpless on the ground the accused forcefully kicked him three times and stomped on him.

"The attack only occupied six seconds but was of such a level of ferocity as to indicate that at the time of the attack from its commencement and until its conclusion, the accused intended to kill Mr Hardy or at the very least to cause him really serious injury."

The trial, before Justice Lex Lasry, continues.