Latimer arrived at Lothian's Te Haroto house at about 3am one morning in September 2018.
There, an associate of Webby and Lothian met him.
A new Court of Appeal judgment showed the two killers then ambushed Latimer, beating his head and hitting him with a shovel.
"Mr Latimer went quiet and a shovel was then thrown at him and he was ordered to dig his own grave," Justice Robert Dobson previously told Webby in court.
"You then resumed your attack on him, with each of you kicking, punching and hitting him with the shovel."
Both attackers dug a shallow grave for Latimer.
Lothian stabbed Latimer many times in his back and side, telling Latimer he was going to die.
Latimer was robbed of pills, meth-smoking pipes, a bag of cannabis and some money.
A post-mortem found stab wounds and blunt force trauma to his face and chest killed him.
Lothian and Webby drove Latimer's car to a remote location and torched it, destroying it.
Webby ended up with a 17 year, nine month minimum non-parole period. He said this was manifestly excessive, and it should have been nine months shorter.
But in its newly published judgment, the Court of Appeal said Justice Dobson was correct to take into account the brutality and callousness of the murder.
The appeal court also said Justice Dobson was right to point out that the murder happened in the course of aggravated robbery, another serious offence.