"I hope that in time he would have realised there was a better way of dealing with the situation rather than having to use his fist."
The Asthanas came to New Zealand eight years ago and Mr Asthana developed a love of the outdoors and an affinity with children.
His mother said he also loved fast cars and was intelligent and generous.
"Unfortunately Tarun came under peer pressure and got pulled into the drinking culture of this country. As a mother I was always wary of what could happen, but he insisted that he was always safe," Mrs Asthana said.
"I tried to make him realise that because of our colour and who we are we always had to careful of how we conducted ourselves."
Mrs Asthana, whose religious faith had helped her cope with losing her son, said she knew he was now in a better place and at peace.
The court was told she had accepted an apology from McFarland and the two parties has undergone restorative justice.
Defence lawyer Ron Mansfield argued for his client to avoid jail. He said McFarland was remorseful and not at risk of further offending.
McFarland had walked away from Mr Asthana after he hit him, but didn't realise how bad the "unintended tragedy" was and did not mean to cause such harm.
When he found out how seriously Mr Asthana was hurt he immediately reported to the Navy, which he had since resigned from, and police.
McFarland was now using his experience to educate others not to use violence in similar circumstances, Mr Mansfield said.
But while she accepted his remorse and other positive factors, Justice Pamela Andrews said only a jail sentence was appropriate.
McFarland, who was on weekend leave, headed to McDonald's near Britomart about 5am after a night out.Inside the restaurant, Mr Asthana picked up a straw from the counter and blew a piece of paper at a woman who was with McFarland.
"You're just standing there looking good, if it was anyone else I would not have done it," Mr Asthana told her.
Outside, he smacked the woman hard on the bottom. She swore at him and told him not to touch her.
McFarland, who was standing at a nearby bus stop eating, heard the altercation and was upset by it.
He placed his food on the ground and walked towards Mr Asthana and saying, "you're being a ******* ****", and punched him once on the left side of his face.
Mr Asthana struck his head heavily on the ground and was knocked unconscious.
McFarland left the scene without helping him.Mr Asthana was placed on life support at Auckland Hospital, which was turned off three days later.