Pistorius had been charged with culpable homicide and negligent driving in the 2008 death of Marietjie Barnard, Eyewitness News in Johannesburg reported.
The culpable homicide charge had been dropped earlier after the state said it was unable to prove the accident alone killed Barnard.
Pistorius would be found guilty even if he were only slightly negligent regardless of how Barnard was driving, Magistrate Buks du Plessis had told the court.
Barnard was clearly speeding and possibly under the influence of alcohol at the time of the accident, the magistrate said. Du Plessis found no evidence Pistorius was driving recklessly the night of the accident.