But prosecutors rejected his plea and jurors ultimately found him guilty of the less serious charges of unlawful imprisonment and assault over the December 2018 death of Bradley Lyons near Lakes Entrance in Victoria's east.
Bottom's barrister, David Cronin, now says his client should be freed from prison after serving four-and-a-half years while awaiting trial, with a discount for having offered an early guilty plea.
Bottom and another man, Rikki Smith, were both acquitted of Mr Lyons' murder in a joint trial alongside Albert Thorn, who was found guilty of his murder.
Jurors heard Lyons was set upon by four men in balaclavas - including Thorn and Smith - and beaten with fists and a metal pole until he bled.
He was then tied up and thrown into a car boot where he was trapped for hours while his attackers plotted their next move.
Mr Lyons was then tortured by the men, who wanted him to confess to allegations he sexually assaulted children.
He was locked inside the boot again and driven by Thorn, Bottom and Smith to Double Bridges, where he was placed in a shallow grave and shot dead.
Mr Cronin made the case for Bottom's swift release in a pre-sentence hearing for the trio on Thursday, where he talked up his client's co-operation with police, including leading them to the location of Mr Lyons' body in May 2019.
Mr Lyons' body was dumped in such a remote location that without assistance from someone with knowledge, it seems almost impossible it would have been found otherwise, Mr Cronin said.
The discovery also provided police with significant other evidence, the court heard.
But Justice Andrew Tinney accepted that while Bottom had offered a plea well in advance of the trial, it was notable that when it came to the crunch in front of the jury he did not plead guilty to anything.
Smith, on the other hand, did plead guilty in front of the jury to intentionally causing injury to Mr Lyons, his barrister John Saunders said.
Smith made frank admissions to police about his part in the assault, including going to Mr Lyons' home with a group of men with the intention of assaulting him.
Statements were read during the hearing on behalf of Mr Lyons' siblings who both credited his support with their survival of a tough upbringing around drug abuse and family violence.
Mr Lyons' teenage stepdaughter also read statements on behalf of herself and his three children. Their mother, Jana Hooper, is also behind bars for her role in Mr Lyons' kidnapping and assault.
The youngsters spoke of bullying, teasing and separation from family, while the 19-year-old pointed out that Mr Lyons was not the only victim of their crimes.
"In saying that, our future will be bright - it'll never hold us back and stop us flourishing," she said.
"Our past does not define us and you cannot stop us from being better people than you could ever be."
The hearing is continuing.
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