An agreed summary of facts outlining the events of that morning was read to the court today.
It said McFarland had been on weekend leave and had gone to various nightclubs before he and a friend went to the McDonald's restaurant near Britomart about 4.50am.
They had consumed alcohol throughout the night, however had done so sensibly and were not intoxicated, the court was told.
There they found a group of young women who they had met earlier that night.
As he was waiting for his meal to arrive, McFarland dropped his drink on the ground.
Mr Asthana, who was also waiting for a meal, turned towards him and began clapping slowly, inviting others to join in.
Mr Asthana then approached McFarland and shook his hand, which McFarland accepted as a joke.
Shortly afterwards, Mr Asthana picked up a straw from the counter and blew a piece of paper at the woman who was with McFarland.
"What the hell?" she said to Mr Asthana.
"You're just standing there looking good, if it was anyone else I would not have done it," Mr Asthana replied.
After receiving her order, the woman went and sat with other friends. Mr Asthana then approached her and began complaining about service in the restaurant.
"He was loud and beginning to attract attention," she said.
Outside the restaurant, Mr Asthana smacked the woman on the bottom with an open palm, which she described as "bloody hard". She swore at him and told him not to touch her.
She told police Mr Asthana thought he was funny and was being a "smartarse".
McFarland, who was standing at a nearby bus stop eating his food, heard the altercation and was upset by it.
He put his food on the ground and walked towards Mr Asthana and said, "you're being a ******* ****", and punched him once on the left side of his face with "significant force", resulting in Mr Asthana falling to the ground.
He struck his head heavily on the ground and was unconscious.
He was placed on life support at Auckland Hospital, where he was pronounced brain dead. His life support was turned off about 72 hours later.
McFarland was granted bail ahead of his sentencing on April 29.
In Dunedin this week, police launched a campaign called "Just One Punch" aimed at highlighting the potential consequences of a single punch.