Dr Charlie Teo will face a second day of questioning by a medical complaints board, having so far defended his decision to perform two ultimately catastrophic surgeries.
The renowned neurosurgeon is the subject of a hearing by the Health Care Complaints Commission, over concerns including that he offered patients false hope regarding their chance of survival.
Under questioning from the commission's counsel Kate Richardson SC on Thursday about why he disagreed with the evidence of other experts, Dr Teo struck a defiant tone extolling his expertise.
He said he would not expect fellow neurologists Professor Bryant Stokes and Associate Professor Andrew Morokoff to know as much about brainstem tumours as he did because it wasn't their specialty.
"It's not just reading a brain scan, it's the nuances of a 'sub-sub-speciality'," he said.
"I have more experience with brainstem tumours and surgery thereof than almost anyone in the world."
At times the controversial surgeon became frustrated by Ms Richardson's questioning.
"I don't blame you for being confused ... but it's what I do for a living," he told her.
The inquiry heard that Dr Teo told a patient she had a five per cent chance of a devastating outcome such as death, locked in syndrome, or complete paralysis.
"Five per cent risk of a bad outcome, means a 95 per cent chance of a reasonable outcome," he said.
In August 2021, the NSW Medical Council restrained Dr Teo from operating without the approval of another doctor after an investigation by the state's health care complaints commission.
He has repeatedly denied any wrongdoing.
