Duduzane Zuma, the son of former president Jacob Zuma, has been found not guilty of the charge of culpable homicide in the Randburg Magistrate's Court.
Zuma was on trial after Phumzile Dube died in February 2014 when Zuma's car crashed into a taxi in which she was travelling.
He pleaded not guilty to the charge.
While delivering his judgment on Friday, Magistrate Tebogo Thupaatlase said the court was mandated to find out whether Zuma was driving negligently or not.
Duduzane Zuma, the son of former president Jacob Zuma, took the witness stand in the Randburg Magistrate's Court on Wednesday to give his version of events on the day Phumzile Dube died.
Thupaatlase said on a charge of culpable homicide state should prove whether the driver of a vehicle was supposed to have seen a possible death. He said negligence must be evaluated in the circumstances of each case.
He said the evidence before the court had established that the weather conditions were bad and that had been confirmed by a climatologist who took witness stand.
Thupaatlase said there was no evidence on record that showed what speed Zuma should have driven on the day that would have avoided the crash. He said three witnesses had testified that aquaplaning could have happened even at low speed.
"There is no evidence that the accused should have foreseen the puddle... There is no evidence showing what steps he should have taken to avoid aquaplaning," he said.
He said the state failed to prove the case beyond reasonable doubt
Zuma said he was travelling from Fourways to Saxonwold and had joined the highway from William Nicol Drive. He told the court that there was heavy rain and poor visibility.
He also told the court that he had been driving at a speed of about 120km/h and had hit a puddle of water, which resulted in his vehicle losing control and spinning.
Submitting closing arguments in the Randburg Magistrate's Court in June, Zuma's advocate Mike Hellens said, if the court took into consideration the evidence submitted by all parties, on the balance of probabilities, it would find Zuma not guilty.
While prosecutor Yusuf Baba argued that Zuma was not a careful driver on the day of the crash, Hellens asked: "What could he have done?"
Baba had submitted that Zuma could have prevented his car from aquaplaning on the day.
Forensic engineer and accident reconstruction expert Konrad Lotter had also corroborated Zuma's defence argument that he had lost control of his Porsche 911 after it hit a puddle of water.
He said it was possible the vehicle lost control due to aquaplaning. It was not necessary that it would have done so at an excessive speed, Lotter had testified.