A dangerously bungled attempt at an apparent citizen's arrest in the remote West Australian Pilbara region has left two men facing potential prison sentences.

A South Hedland jury took just a few hours on Thursday to find Robert Peter Butson and Zachary Kane Armstrong guilty of dangerous driving causing grievous bodily harm and then attempting to cover it up in May 2016.

The men told police they did not mean to hurt anyone but wanted to catch one of the local youths they blamed for a series of break-ins around their neighbourhood.

Instead the victim, a 14-year-old cyclist, was left to 'crawl, hop and drag himself' to help after a midnight chase along a dirt track that ended in him falling from his bike and badly breaking his leg.

The small car, driven by Butson, with Armstrong and a large mastiff dog on board either collided with the bike or caused the teen to fall from it.

It is a case that holds startling similarities with that of 14-year-old Elijah Doughty, who was killed just months later in another regional WA town when he was run over on a dirt road by a man trying to recover a stolen motorbike.

Who was to blame?

The complicated task left to the jury was to decide whether Butson and Armstrong were criminally responsible for causing the boy's injuries.

The teenager tried to flee on his bicycle across The Flats, the Supreme Court was told. ( ABC North West WA: Ewan Gilbert )

The task was made more difficult because both of the accused men and the teenage victim admitting to lying about what happened.

The victim denied being involved in any wrongdoing, and no evidence was offered to say otherwise.

On the night in question he was hanging around a group of up to 10 other teenagers, at least one of whom was spotted by Armstrong attempting to gain entry to his home shortly before midnight.

Prosecutor Anthony Eyers told the court the victim's mistake was to be the only one in the group on a bike.

"[Butson and Armstrong zeroed] in on the cyclist … as he was the only one they could pursue in a car," Mr Eyers said.

'Simply a concerned resident'

Neither Armstrong nor Butson gave evidence during their near two-week trial, though in police interviews admitted to chasing the teen and then destroying the car afterwards by fire.

Butson's lawyer Damien Cripps told the South Hedland Supreme Court his client was 'simply a concerned resident of South Hedland' hoping to help the youths see the error of their ways.

"I just [wanted] to talk to the kid … and tell him what they're doing is not on," Butson told police after his arrest.

The court heard the teenager had to be flown to Perth for medical treatment. ( ABC North West WA: Ewan Gilbert )

"Say it's not that hard to … get yourself a part time job … earn your own money and not steal from others."

Armstrong's lawyer Andrew Monisse urged the jury to 'put [themselves] into Mr Armstrong's shoes'.

"[After weeks of break-ins] you just want to try and end it someway," he said.

The prosecution labelled that idea 'ludicrous'.

"The intention was to give some law and order social lecture? Do you think so? Do you think so?" Prosecutor Anthony Eyers said.

Armstrong and Butson will be sentenced later this year.