Both vehicles were extensively damaged, and all four involved in the crash suffered serious injuries.
Rothnie was still suffering the effects of a concussion and has a hearing loss; the Crown told the court.
Bickley told the jury that his then-partner twice grabbed the wheel as they headed home with "a lot of more force" the second time, and told him she was going to kill them both.
A nurse, who gave first aid to Bickley and Paul at the scene, said when Paul had regained consciousness, without prompting she admitted she caused the accident.
Paul, who suffered some injuries, including a head injury, told police she had no recollection of the crash when she was interviewed about a month later.
A police crash analyst said that the yaw marks and gouges on the road were evidence of a "sudden forceful" turning of Bickley's car to the right, with no signs of braking.
Justice Rebecca Edwards convicted Paul of both dangerous driving causing injury charges and remanded her on bail for sentencing at a later date yet to be scheduled.
Paul's bail conditions include a ban on her driving any motor vehicle and travelling out of the country. She was earlier had to surrender her passport to the court.