Senior Constable Jimmy Hayward from Southern NSW Police Crash Investigation Unit appeared in Wagga Local Court on Thursday to give evidence during a joint committal hearing for two men accused of engaging in a street race that led to Mr Smith's death.

The incident occurred on Coleman Street as Mr Smith was reversing out from his workplace.

Matthew Thomas Cahill, 19, of Batlow is facing charges of manslaughter, two counts of dangerous driving occasioning death, causing bodily harm by misconduct, negligent driving occasioning death and acting with the intention to pervert the course of justice.

Joshua Aaron Byrne, 21, of Ashmont is facing charges of manslaughter, two counts of dangerous driving occasioning death, negligent driving and cause bodily harm by misconduct while in charge of a car.

Both men appeared in court on Wednesday and Thursday and have not entered their pleas.

Michael King, defence barrister for Mr Byrne, questioned Senior Constable Hayward about whether he ensured that Mr Byrne knew his rights during a police interview while he was in hospital after the crash.

Mr King argued that the officer gave unclear instructions to Mr Byrne about his right to silence and his obligation to answer questions about the crash.

Senior Constable Hayward said he gave proper instructions to Mr Byrne during an informal discussion before a recorded interview.

Mr King said that the interview transcript showed contradictory evidence.

"You were determined to not clearly explain his rights to him," Mr King said.

To which the officer said: "There were no objections from Josh or his mother [who was also present during the interview]."

The officer was also questioned about his consideration of Mr Byrne's physical condition before interviewing him on the evening after the crash.

"When the interview started, the assessment [of Mr Byrne's condition] continued ... there was no objection," Senior Constable Hayward said.

He was also questioned about his investigation into the airbag of the Commodore that crashed into Mr Smith's ute and about the implications of delay because he had to travel from Wollongong.

Earlier in the hearing, a civilian witness told the court about the collision after seeing two cars speeding past him.

The matters have been adjourned until July 24 this year.

While you're with us, did you know that you can now receive updates straight to you inbox each day at 6am from The Daily Advertiser? To make sure you're up to date with all the Wagga news sign up here.