A South Australian man accused of bashing a trucking company owner to death with a spanner has won a new trial.
Jesse Ray Penhall, 41, was found guilty of the murder of 39-year-old David Norris at his trucking yard at Salisbury, in Adelaide's north, in September 2017.
But the Court of Criminal Appeal on Friday set aside the verdict, ruling the trial judge had erred in not giving proper directions to the jury in relation to Penhall's claims that he acted in self-defence.
In his published reasons, Justice Kevin Nicholson said the trial judge's failure to explain how important aspects of the evidence might relate to self-defence and partial self-defence meant that the jury was not provided with the level of assistance necessary for a fair trial.
The court also found the judge had erred in not leaving provocation as a pathway for a verdict of manslaughter rather than murder and, as such, there had been a miscarriage of justice.
Jurors in the trial were told Mr Norris was found in a pool of blood on the floor of his workshop and had suffered at least six blows to the head.
Prosecutor Jim Pearce said on the day of the killing, Penhall had gone to the trucking yard and, at first, his meeting with Mr Norris was amicable.
Mr Pearce said exactly what went wrong was not known but Mr Norris had ended up dead.
In his evidence at the trial, Penhall said it was Mr Norris who had first attacked him and he had feared for his life.
A date for a new trial is yet to be determined.