The murder trial of musician Molemo "Jub Jub" Maarohanye and his co-accused Themba Tshabalala was postponed by the Protea Magistrate's Court on Monday.
"The matter is postponed to May 14 for accused number two's [Tshabalala] case," magistrate Brian Nemavhidi said.
"The case against accused number one [Maarohanye] is provisionally closed for the expert testimony."
This was expected to be an IT expert who would challenge the authenticity of cellphone video footage presented by the State earlier in the trial.
State prosecutor Raymond Mathenjwa told the court he would need time to study the witness's evidence, and would be out of the province on official business from Monday evening.
On Monday morning, Mathenjwa cross-examined eyewitness Mphumelelo Vezi.
Vezi was a passenger in Tshabalala's car when it allegedly collided with Maarohanye's car on Mdlalose Drive in Soweto on March 8, 2010.
One of the cars ploughed into a group of school boys, killing four of them, and leaving two others brain damaged.
Tshabalala and Maarohanye were allegedly drag-racing at the time.
Vezi told the court the left rear of Tshabalala's blue Mini Cooper hit the right rear of Maarohanye's grey Mini Cooper.
"I did not see it, but I felt it and I heard it... The bang was loud, but not very loud. I was sitting on the left rear of the blue car, where the bang was," he said.
Questioned about his initial statement, Vezi said when he used the term "swerve" to describe what Tshabalala did, it was incorrect because Tshabalala moved back into his lane.
"So you are now conserving the second mistake in your evidence," Mathenjwa said. Vezi replied: "There is always room for error."
Photographic evidence in court showed the petrol cap, paint, window and tyre were intact on the left rear of Tshabalala's blue Mini Cooper.
Mathenjwa asked: "Do you see any corresponding damage to the loud bang you heard?"
"No," replied Vezi.
Mathenjwa then asked him to match the damage to the cars on photographs.
"I don't know how you want me to answer that. I heard a loud bang... I heard a bang on the side of the car," said Vezi.
Mathenjwa asked: "What you heard, is it supported by the evidence?"
"No, sir," Vezi replied.
Vezi told the court Tshabalala and Maarohanye knew each other through him.
In March, Vezi told the court that Tshabalala was responsible for the 2010 crash. He said Tshabalala had tried to overtake Maarohanye while a minibus taxi was approaching about 40 metres in front of them.
Maarohanye and Tshabalala are on trial for murder, attempted murder, and driving under the influence of alcohol and drugs.
Tshabalala wore a black suit in court on Monday. Maarohanye was in a brown leather jacket and black jeans.