Crown prosecutor Clayton Walker argued former navalwoman Sayers deliberately drove across the road into the path of the car driven by kindergarten teacher Ms McGarva, who was on her way to an RSA quiz night.
But defence counsel Eric Forster countered that while police investigations found no accidental cause the Crown was unable to eliminate some possible factors, and was therefore unable to establish it was deliberate.
Evidence was given that Sayers had just minutes beforehand argued with boyfriend Shane Phillips, who told her it was "over" and she had to leave their unit in Tamatea.
Her response was not good, he said. She scratched and kicked at him, and then drove off.
The jury was told Sayers was on anti-depressant medication at the time, and had several months earlier told a friend that she had self-harmed while in the navy some years earlier. She had said being with Mr Phillips was the best thing that had happened to her, and she would "probably" kill herself if the relationship was to end.
Detective Stacey Bailey, the last of seven people giving evidence for the Crown, said that following the crash she had two meetings with Sayers and her lawyer, but she declined to make any statement. She was charged at the second meeting in March this year.
Mr Forster decided against calling any witnesses for the defence in the trial and
argued that while the police investigation established no accidental cause, the Crown had not eliminated other possible factors such as an animal on the road, other distraction or the stress Sayers had been under in the hours leading up to the crash.
No other charge was laid in relation to the crash.