The cause of a road crash in which a man was seriously injured cannot be determined without a report into the mechanical condition of the car, the Supreme Court heard yesterday.

An expert witness told the jury he could not be certain whether driver error or a vehicle fault caused the smash because no examination of the vehicle’s condition had been carried out.

John Wardman, of Paget, denies causing grevious bodily harm to Alexander Doyle while driving over the legal blood-alcohol limit, driving while impaired and failing to provide Mr Doyle with the necessaries of life on December 27, 2010.

Prosecutors allege Mr Wardman was driving home with his brother, Christopher Wardman, and Mr Doyle after a night’s drinking when he crashed into two walls in Paget.

Mr Doyle suffered extensive bleeding and bruising in his brain, and the Crown has argued the defendant focused on getting the vehicle towed rather than seek medical help for his friend.

The court heard last week that Christopher Wardman initially told police he was responsible for the crash, although officers said he reversed his version of events almost immediately after being arrested, fingering the defendant as the culprit.

Mr Doyle told police in March 2011 that Christopher Wardman had been behind the wheel on the night of the crash while placing the defendant in the passenger seat. But he told the court last week that at the time of his first interview, he was still struggling with memory issues caused by the crash.

Expert witness James Keenan, an accident investigator with an English forensic engineering company, Keith Borer Consultants, told the court yesterday he could not determine exactly what or who caused the smash because he did not have enough information to do so.

Questioned by defence lawyer Marc Daniels, he said he had 30 years of experience as a police officer with Merseyside Police in Liverpool, England, 20 of them as a collsion investigator, before joining Keith Borer.

He said he had analysed a report by Bermuda Police Service Inspector Philip Lewis, of the Traffic Collision Investigation Unit, but this did not include a mechanical report.

Mr Keenan said: “You can’t rule out the possibility a mechanical defect caused [the car] to go out of control.

“I’ve not seen any vehicle examiner’s report to establish the mechanical condition of the vehicle.

“It’s important to all collisions because we have got to establish the cause of collision and to rule out road conditions, mechanical difficulties ... then you’re left with human error. It’s part and parcel of investigating accidents.

“You look at the mechanics of a vehicle. In this case, the vehicle was attempting to turn left from a major road to a minor road and for some reason it collided with a wall. A vehicle examination would look at the suspension and steering to ensure nothing was wrong with that. It would also look at the tyres — under-inflated tyres can cause difficulties with turning.”

Mr Keenan said the doors, windows and seat belts should also have been examined to assess whether they were working properly. He said looking at the seat belts would have determined if they had been used but could not determine who was driving.

Earlier yesterday, Inspector Lewis told the court no examination into the mechanical workings of the car had been carried out.

Mr Daniels asked him: “How do you know John Wardman wasn’t the passenger and tried to climb out the car window?”

“I don’t know but it’s very unlikely,” Mr Lewis replied.

Mr Daniels suggested Mr Lewis’ expert opinion was more of a “best guess” because he did not examine the car firsthand but based his report on photographs and witness statements.

Mr Lewis said: “Based on all the evidence I had, based on my knowledge and experience, it’s my opinion.”

The trial in front of Puisne Judge Charles-Etta Simmons continues.