The court heard Mr Tate, 31, had been driving in a convoy through the dunes at night with a blood alcohol level of 0.122 per cent and Misha Frankee Ramanauskas travelling on the roof of his Nissan Patrol.

The prosecution said evidence showed Mr Tate had not stopped at the top of a dune and had braked all the way down, throwing the full weight of the vehicle to the front and causing it to flip and land on its roof, crushing Mr Ramanauskas underneath.

Despite efforts by Mr Tate’s brother Tyson, who performed CPR, Mr Ramanauskas died of chest injuries.

One of the passengers, David Bell, said Mr Tate’s speed earlier in the night had been so sedate that at one stage he might have even considered getting up on top of the roof himself.

According to passengers, Mr Tate's speed with Mr Ramanauskas on the roof, did increase slightly but because they were on relatively flat ground, the general mood in the car continued to be one of fun.

Senior Constable Paul Woolsey of the Major Crash Investigation Unit, told the court it appeared to him from photos of the accident site that Mr Tate had not stopped at the top of the dune but had starting braking as he went over the brow of it.

The court watched Mr Tate's video interview with police and heard him describe the horror of realising his friend was under the vehicle and his frantic efforts to dig him out or roll the vehicle back off him.

Mr Ramanauskas' urine alcohol level, at the time of his post mortem registered at 0.234 per cent.

Mr Tate's defence counsel, Steve Walker, said one of the key issues of the case was whether his client had driven in a manner that was dangerous.

The defence case also touched on the legality of whether the Wylie Bay dunes area was an area where the public were permitted to be.

Ms Selma Faahan-Smith, a director of the Wylie Bay Pastoral Company which owns the land, said they had never given permission for people to go four-wheel driving there, but acknowledged that there were no signs, gates or barriers preventing people from accessing the dunes.

After the verdict was given Steve Boni, solicitor for Mr Tate, told the Esperance Express: "We acknowledge that there has been a death and a significant loss to the Ramanauskas family and that is a very heartfelt loss for Michael as well. This is something he has to carry with him for the rest of his life. There are no winners."

"It was an accident that could have happened to anyone who uses the dunes. This incident should at the very least, get some action happening from the relevant authorities as to how best manage the safest recreational use of the sand dunes."