Smith, 36, drove forward 6.9 metres, crushing Ewan Sams against the backyard garage of his NSW Hunter home and causing fatal injuries.
Smith, with Mr Sams' ex-girlfriend Kirby Armstrong in the passenger seat, then reversed out of the gate and drove off.
A statement of agreed facts released by the Newcastle Supreme Court reveals details of what happened on that night at Cessnock on September 25, 2018.
Smith had been due to stand trial for murder on Monday before the NSW Director of Public Prosecutions agreed to accept his guilty plea to the lesser charge of manslaughter.
The statement of facts told how Smith and Ms Armstrong drove to Mr Sams' home at about 11pm because he was refusing to hand back her belongings. Mr Sams claimed Ms Armstrong owed him money.
Having crashed into the gate to access the backyard, Smith backed up a short distance after Mr Sams came out with a baton and threatened to smash his lights.
Ms Armstrong got out of the 4WD and approached Mr Sams as Smith stayed in the vehicle.
Mr Sams at this stage was going in and out of the house getting piles of Ms Armstrong's belongings to put on a fire in the backyard.
Police said Mr Sams was "raving on" about what Ms Armstrong owed him before grabbing her and saying: "You know that I love you. I can't handle having your stuff around any more."
When Ms Armstrong went to the back door, Mr Sams put her arm behind her back and held her close so she couldn't move before bending her backwards over a railing.
By this stage, Smith had driven the 4WD through the gates and stopped.
Ms Armstrong broke free and was walking back to the 4WD when Mr Sams told her that her birth certificate was in the fire and "I'll start with your Dad's stuff next".
She screamed at Mr Sams before getting back in the 4WD saying: "Please just let me have my Dad's stuff 'cause he's deceased and you still have parents to buy you stuff."
Mr Sams ran at the 4WD and tried to lift Ms Armstrong out when Smith yelled at him to leave her alone.
Smith told Mr Sams: "You're not f***ing taking her mate, stop it."
Mr Sams picked up a metal pole and told Smith,"I'm gunna kill her" and "you can f***ing have her".
Mr Sams then picked up a paver and smashed the windscreen.
After Smith unsuccessfully tried to reverse out, Mr Sams threw the paver at him so Smith accelerated towards him, crushing him against the garage.
Mr Sams, 36, screamed "stop" several times after being struck. He was bent slightly forwards over the bonnet with his right hand up and his palm facing the 4WD.
Smith then reversed and as he was driving off Ms Armstrong tried calling triple zero but her mobile phone battery was dead.
Police and paramedics tried to revive Mr Sams but he was pronounced dead at 11.54pm.
Summarising the case, police said Smith was high on methylamphetamine when he drove into and seriously injured Mr Sams but he did not deliberately intend to cause his death.
A sentence hearing for Smith will be held on Thursday.
17°C