Tumelo Mokoka's friend Maarohanye and co-accused Themba Tshabalala are on trial on four counts of murder, two of attempted murder, reckless and negligent driving and driving under the influence.
The pair is alleged to have been drag-racing while high on morphine and cocaine when they crashed into six children on March 8 2010. Four pupils were killed. Two were seriously injured.
Under cross-examination, Mokoka said Maarohanye was wrong when he told the court that they were "lost and driving in circles" before entering Mdlalose Street before the accident.
"I did not know the directions exactly. But I was given directions by the guy I was talking to over the phone. We never went in circles," Mokoka said.
He insisted that Maarohanye's silver-grey Mini Cooper never spun after being bumped, he never mentioned a BP garage or Chicken Licken outlet to Tshabalala and that he did not remove Maarohanye's seatbelt after the crash.
But he corroborated Maarohanye's evidence that Tshabalala was driving in the right-hand lane, almost parallel to Maarohanye's vehicle just before the accident.
Prosecutor Raymond Mathenjwa put it to him that Maarohanye's evidence was that he had unclipped his seatbelt before pulling him out of the car through the sunroof.
He also said he never agreed that Tshabalala would lead the way to the said BP garage or Chicken Licken outlet. All this contradicted Maarohanye's version in evidence in chief and cross-examination.
Mokoka also got stuck when Mathenjwa challenged him on differences in his statement to police and evidence presented in court.
"In the statement (to police) you said you saw the collision (between Tshabalala and Jub Jub) but today you say you only heard the sound. Why do you change?" Mathenjwa asked.
Mokoka responded: "It was a mistake. I did not know it was a critical point until now. I am not a lawyer."
Mathenjwa told him that he did not need to be a lawyer to know the truth and what was not the truth.
The trial continues.