The Crown alleges Sayers, whose family lived at Puketapu, caused the crash by an unlawful act of dangerous driving and in an opening address prosecutor Clayton Walker told Justice Denis Clifford and a jury of nine men and three women the only issue to decide was whether it was deliberate.
But defence counsel Eric Forster said the Crown would be unable to prove it was, and could not rule out other possible causes, such as an animal crossing the road or other distraction.
Police Eastern District serious crash unit investigator Cory Ubels said no other vehicles appeared to have been on the same straight of Prebensen Drive when the crash happened, so there were no witnesses.
While there had been some rain earlier, there were no skid marks or other evidence that weather was a cause, vehicle examinations found no mechanical defects which could have been responsible, and there was no evidence of alcohol or other impairment, although Sayers was using prescription anti-depressants.
In answer to questions put by the judge at the request of the jury, Mr Ubels said the vehicle speeds were not able to be established, but the fact that Ms McGarva's car came to an almost immediate stop and Sayers' vehicle "tumbled" and came to rest about 65-70 metres away indicated she was travelling at a greater but not necessarily excessive speed. He said her car appeared to have veered across the road rather than switch straight across into the path of Ms McGarva's car.
Asked by Mr Forster if being agitated and upset could be a sufficient distraction, as in the "phenomenon" of switching-off, Mr Ubels said he didn't believe it would be such a distraction as to veer across the road "and not do something about it".
Napier woman Shelley Soanes told the court that several months before the crash Sayers told her that when she was in the navy she had experienced depression and at one stage tried cutting her wrists. Sayers had said that her new boyfriend, whom she had been with for more than a year, was the "best thing" that had happened to her. She did not know how she would cope if she were without him, and that she would probably kill herself if it ended.
Ms Soanes said it concerned her, and she looked for wrist wounds but, while not disbelieving, considered it may have been attention-seeking. Sayers had before the discussion been using "herbals" and had smoked cannabis, and was emotional and drinking at the time.
She said she had known Sayers' boyfriend for many years, and became aware a sexually suggestive text message she (Ms Soanes) sent to his phone which Sayers had borrowed, sparked her anger. But the woman said there was no sexual relationship between herself and the man, and her message was part of the way they communicated.
Sayers' father said he was aware of his daughter's depression. He told Mr Forster the crash scene was on a route between town and their Puketapu home, and added: "It was usually the first place she headed for when she had a problem."
The trial is a second attempt to hear the case, the first having started on Monday but being aborted by the judge because legal issues had arisen. A new jury was empanelled yesterday.
