A Canberra driver has been cleared of causing a car accident that killed his wife, despite recording a high cannabis reading in the aftermath of the crash.
Troy Anthony Wilson pleaded not guilty to negligent driving occasioning the death of Lisa Wilson, his wife of 18 years, on September 13, 2009.
Mrs Wilson suffered massive head injuries and was pronounced dead at the scene after the car, driven by Mr Wilson, left Paddy's River Road at a bend and rolled down an embankment.
Mr Wilson's four children and his cousin's two children were in the blue Mitsubishi Pajero at the time.
The group were returning to Canberra after a Sunday barbecue at the Cotter picnic area about 7pm.
The children and the defendant suffered minor injuries.
The 40-year-old told the ACT Magistrates Court at a 2011 hearing that he was approaching the bend when he spotted a kangaroo in the middle of the road.
He said he swerved and hit gravel, losing control of the vehicle.
A blood test conducted about two hours after the incident showed Mr Wilson had a high cannabis reading which suggested he had consumed the drug shortly before the incident.
But Mr Wilson revealed he smoked three or four joints of cannabis a day for pain relief and had not consumed cannabis since the previous evening.
A medical expert told the court the level of cannabis detected would likely impair Mr Wilson's driving skills but could not say how seriously.
The prosecution also alleged the accident was caused by the car travelling into the bend too quickly. The speed limit on the road was 100km/h but an advisory speed sign recommended navigating the curve at 45km/h.
A police investigation estimated Mr Wilson negotiated the bend between 79km/h and 83km/h, while a test drive revealed an officer could safely take the corner between 75km/h to 80km/h.
Magistrate Peter Dingwall acquitted Mr Wilson in a decision published earlier this year.
Mr Dingwall said he could not be satisfied beyond reasonable doubt that the accident was the result of negligent driving by Mr Wilson.
"There is no basis for finding beyond reasonable doubt that the defendant was affected by cannabis to such an extent that it affected his judgment as to the appropriate speed at which he should have entered the bend, nor that it affected his judgment, reflexes and reaction time when confronted with a kangaroo on the road just ahead," Mr Dingwall wrote in his judgment.
"There is simply no basis for a finding that it was the speed of the vehicle into the bend which caused the defendant to lose control of the vehicle's steering.
"In my view, in these circumstances, it simply cannot be found that the ordinary prudent driver, so confronted and needing to make an instantaneous decision, would not decide to swerve the vehicle and not apply the brakes. In my view, to find otherwise would be placing too high a standard on drivers."