Rahman appeared in Auckland District Court yesterday morning and pleaded not guilty to charges of careless driving causing death and making a false entry in his logbook.
Auckland Co-op Taxis chairman Jacob Patel said the company had worked with police as they investigated the case, providing them with the CCTV footage from inside the cab, as well as documentation.
Police also took the vehicle for testing.
"Suddenly he got a letter saying they were going to charge him," Mr Patel said.
The charges were denied by Rahman but outside court he was advised by his lawyer not to discuss how he planned to defend the matter.
Mr Patel confirmed he was still working for the company as the P endorsement on his driving licence had not been suspended.
However, the company had recently taken a hard-line stance against drivers with convictions in the wake of the case of 36-year-old Amandeep Singh, who admitted driving while four times over the breath-alcohol limit in January.
Now anyone with a conviction would be barred from working as a driver, and Mr Patel said Rahman would be no different if convicted.
Mrs Luo's family voiced their frustration shortly after the tragic incident but the target of their anger was not the man before the court.
The family said they had repeatedly warned Avonlea about Mrs Luo's history and believed her death could have been prevented.
"We strictly told the employees there, many times, to never let her out by herself - they all know," said Mrs Luo's granddaughter Emily Liu.
But rest home owner Steven Tan said by law they were not allowed to restrict the movement of their clients, unless they had dementia. Undeterred, the family took their complaint to the Health and Disability Commissioner.
A commission spokeswoman would not provide details of the investigation but yesterday confirmed it was ongoing.
Mr Tan said the commission had sent him a list of more than 20 questions to which he responded some months ago. He was confident staff had "done the right thing".
Rahman will appear in court again next month.
Careless driving causing death carries a maximum penalty of three months in prison, a fine of $4500, along with a minimum driving disqualification of six months.