Bennett "Ben" Dominick died shortly after he disappeared somewhere in the arid and remote Coocoran Opal Fields in northwest NSW in January 10, 2015, Coroner Teresa O'Sullivan found on Thursday.

"Whether Ben's death was the result of homicide or misadventure, and to a much lesser extent suicide, cannot be excluded," she said.

"However, I have serious suspicion that Ben was subject to foul play."

Police have conceded flaws in the investigation's infancy crippled the chance of finding him alive.

Mr Dominick's car still had money inside when found on January 13 abandoned in bushland 30km from where he was last seen.

He'd been reported missing hours earlier but it took another week for police to conduct a formal search.

Significant merit was given to a local officer's "certainty" that she had seen the missing man at a petrol station on January 12.

Lightning Ridge police didn't inquire about obtaining copies of CCTV from Caltex or nearby businesses until January 20, the coroner said.

"This is not a case where Ben disappeared without a trace," Ms O'Sullivan said.

"Rather, the fact that his car was parked in Lightning Ridge was a significant clue as to his possible whereabouts."

Ms O'Sullivan said had police focused on the evidence before them on January 13 "the chances of finding Ben would have greatly increased".

She concluded the car was not driven to its resting place by Mr Dominick but "regrettably" was unable to say who did or why they drove it there.

Police told the inquest the mistakes that occurred in 2015 wouldn't be possible under a new regime introduced this year.

An officer entering a missing person report into the police database must now conduct and record an initial risk assessment and submit it to their supervisor for review and verification.

When new information is entered, police are prompted to consider reassessing the risk.

The Missing Persons Registry also reviews each new report within 24 hours of its creation.

The coroner recommended Mr Dominick's case be referred to the Unsolved Homicide Team.

Australian Associated Press