The second and third times he hit him were “excessive”; the threat had passed and Robertson was lashing out in anger, not fear, Newcastle District Court has heard. 

Moments earlier, Robertson claims Mr Daunt had put a semi-automatic pistol to his head and accused him of being a police officer. 

"You're either a copper or you're trying to rip me off and I'm gonna kill you," Mr Daunt said, according to the account Robertson gave police when he finally confessed to the killing more than a year later.

Robertson told police Mr Daunt forced him to his knees, kicked him a number of times and was yelling threats at him with the gun pointed at his face when Robertson grabbed a hammer from an open tool box and swung it at Mr Daunt. 

He told police he knocked Mr Daunt's hands out of the way before striking him in the temple with the hammer.

Mr Daunt fell on his back and Robertson jumped on top of him, striking him at least two more times in the head with the hammer "because he was so angry". 

Robertson said he then went to choke Mr Daunt, but realised he was dead. 

But it was what Robertson did after killing Mr Daunt that has perhaps troubled the popular 27-year-old builder’s family the most.

First he dumped the body in bushland off George Booth Drive at Mount Sugarloaf and then he started sending texts to Mr Daunt’s mother, Denise, purporting to be her son; first suggesting he was contemplating suicide and then saying he was fleeing to Perth because someone was after him. 

Those texts sent the family on an “emotional rollercoaster” in the weeks after Mr Daunt was first discovered missing, according to emotive victim impact statements read by Mr Daunt’s parents and siblings in court on Friday. 

Robertson pleaded guilty to manslaughter by reason of “excessive self defence” and was sentenced to a maximum of five years and 10 months in jail, with a non-parole period of three years.