Suncorp has won a claim dispute after a woman was involved a car accident when she chose to drive home after three glasses of white wine at a barbecue.

The NSW-based motorist was an approved driver on a Suncorp motor insurance policy which had an exclusion for driving by anyone who was under the influence of, or had their judgement affected by, any alcohol, drug or medication.

She consumed several glasses of wine with her family at a spring gathering two years ago. Though she felt fine, she suspected she may be just over the legal blood alcohol driving limit and checked using a personal breathalyser.

That reading was under the limit and so she proceeded to drive home. During the journey, she turned right on a green arrow at an intersection controlled by traffic lights and collided with a vehicle travelling from the opposite direction – occupied by a man and his pregnant partner - at around 8pm, less than half an hour from her last drink.

She alleged the accident was caused when the other party drove through a red light. She did not see the other vehicle and she did not brake. The male driver said he swerved slightly to the left but the two vehicles collided, causing damage to the front right-hand side of his car.

An attending police officer confirmed the woman appeared slightly affected by alcohol but said she showed no signs of stumbling and her movements were normal. The officer was unable to determine whether her speech was affected by alcohol or her “understandably emotional” state. He reported no overpowering smell of alcohol.

The policyholder went to the Australian Financial Complaints Authority (AFCA) after Suncorp declined the claim on the basis of its exclusion, arguing the alcohol was not a contributing factor to the accident and so the claim should not have been refused.

AFCA ruled in Suncorp’s favour, saying the influence of alcohol was capable of causing or contributing to the loss.

“She was aware she was close to the legal limit but chose to drive. The exclusion is a well-known term of insurance policies,” AFCA said.

“The evidence suggests the woman appeared slightly affected by alcohol. Even assuming she was turning right on a green arrow, she has an obligation to keep a proper look out and to avoid a collision.

“It is not possible to be satisfied that alcohol was not a contributing factor. But for the influence of alcohol, she may have been able to brake and reduce the impact.”

As the Road Transport Act 2013 (NSW) does not allow certain evidence in relation to insurance to establish a person was affected by intoxicating liquor, Suncorp provided two expert reports calculating what the driver’s most likely alcohol level would have been at the time of the collision.

A forensic pathologist concluded her alcohol level would have been steadily rising and peaked at approximately 8.30pm. At the time of the accident, her alcohol level was likely to have been 0.08.

At this level, a driver’s perceptions, judgement and reaction skills would be significantly impaired - a key factor in the collision.

“Suncorp has shown the woman was under the influence at the time of the accident,” AFCA said.

Following the accident, the other driver accompanied his pregnant partner to the hospital. When contacted by police, he could not remember what colour the lights were but later attended his local police station and said he was travelling in the far-left lane with a green light and the woman had turned in front of him.

Police were unable locate any witnesses and due to the conflicting versions, could not determine who was at fault.

“Driving under the influence of alcohol is capable of causing or contributing to a collision. The burden of proof is on the complainant to prove absence of causal connection or contribution,” AFCA said.

See the full ruling here.