Fairfax today reported findings into the triple fatality with coroner Chris Devonport revealing the man behind the wheel, Rigby, had methamphetamine in his blood at the time.
The court heard expert advice that showed methamphetamine adversely affected drivers by making them overconfident and prone to "taking unnecessary risks, aggressive and dangerous driving and impaired ability to react appropriately".
The coroner also revealed details of the crash investigation which showed the Inspire the four gang members were in had crossed the centreline as a second car tried to overtake it on a corner.
Marks on both vehicles showed they touched before the second car, a Honda Prelude braked heavily, then stopped as it hit the barrier at the edge of the cliff.
At that point the Inspire crossed in front of it, hitting the barrier at speed before mounting it and flying over the top.
Fairfax reported the car touched the ground briefly on the other side of the barrier before it became airborne off the near vertical drop.
There were no witnesses and the second car involved in the accident drove off, said the coroner.
In the days after the crash a hunt was launched for a second car believed to be involved in the crash. It was handed over to police nearly a week later but no one has ever revealed who was driving the car.
The accident's sole survivor, Atkinson, was found alive on the bank of the river at the bottom of the cliff wearing just a pair of jeans. He had a graze on his face and bruising on his left arm but was capable of walking and talking. He had been in the front passenger seat and was wearing a seatbelt.
Fairfax reported that Atkindson told police Rigby had "just lost control and we went over". He said he did not see any other cars and did not think another car was involved.
