Driver in fatal crash not guilty

A man has been cleared of careless driving after a fatal crash because a judge agreed with experts that it could have been a freak accident.

Jonathan Butt, 61, was driving north through rain and buffeting wind when his trailer flipped into oncoming traffic on State Highway 1, in Clarence, north of Kaiko¯ ura.

Witnesses said Butt took a bend at about 90kmh, despite it having an advisory speed limit of 65kmh.

Police charged him with careless driving causing death and injury.

But experts said it was possible the crash was a freak accident, where strong winds and sloshing fuel combined to tip the trailer.

Police claimed Butt was driving too fast for the road and weather conditions, but Butt pleaded not guilty and the case went to a judge-alone trial at the Blenheim District Court last month.

Butt told the court he had stopped south of Kaiko¯ura after hearing a ‘‘squawky noise’’ from the trailer on the morning of June 9, 2015.

But the trailer looked fine so he carried on, he said.

As he reached the sweeping lefthand bend near Clarence River Rafting that afternoon, he felt the trailer wobbling significantly moments before the crash, he said.

Butt was afraid the trailer had become unhinged and was trying to focus on getting around the corner without crossing the centre lane so he could pull over safely, he said.

But the trailer flipped into oncoming traffic, hitting William McCallum’s van.

McCallum, a 77-year-old Blenheim man, was killed in the crash, and his wife seriously injured.

A witness driving a truck and trailer behind Butt told the court they were both going up to 95kmh when the crash happened.

The wind was gusting up to 60kmh, he said.

Butt believed he was going between 60kmh and 70kmh, saying that a person would have to be ‘‘pretty loopy’’ to take the corner at 90kmh.

Tasman Crash Investigation Unit Senior Constable Greg Taylor said he calculated Butt was going about 78kmh.

Police found the trailer coupler was bent and fractured by overloading, but it was impossible to tell when the fractures were caused.

The damaged coupler was unlikely to have caused the crash, Taylor said.

He believed Butt’s speed was the cause of the crash, but the strong wind and the sloshing of fuel in the generator tank could have made the trailer unstable, he said.

Private investigator Paul Bass, who specialised in crash reconstruction, and forensic mechanical engineer Andrew McGregor said speed was not the cause of the crash.

McGregor said the layout of the land could have funnelled the southwesterly wind across the highway with great force.

The sloshing of fuel and the strong wind could have caused a phenomenon known as ‘‘resonance’’, or divergent oscillatory behaviour, where the combination of forces tipped the trailer, he said.

McGregor believed resonance caused the crash.

Judge Tony Zohrab said in his decision released yesterday that he did not believe Butt or the witness to be lying, but either of them could have been mistaken about their speed.

Expert evidence caused him to accept the possibility Butt’s driving did not cause the crash, but rather circumstances outside of his control, he said.

Judge Zohrab found Butt not guilty on both charges.