Nicola Annabel Teo from Bondi, was accused of dangerously driving on the wrong side of the road when she hit former Comancheros boss Jock Ross at Lower Macdonald, northwest of Sydney in 2019.

Now in his late 70s, Mr Ross was airlifted to Westmead Hospital in a critical condition after his motorcycle collided head-on with Ms Teo's Toyota Landcruiser.

His daughter Holly Gittany told reporters outside Sydney's District Court on Tuesday the outcome was "just not right".

"My dad will never be the same again," Ms Gittany said.

"My dad was severely injured.

"I was told that morning he wasn't going to survive."

The 26-year-old was facing a maximum jail term of seven years and had pleaded not guilty for the serious charge of dangerous driving occasioning grievous bodily harm.

She also faced charges of negligent driving, not keeping left of the dividing line and not giving particulars to police following the crash on Settlers Rd near Wisemans Ferry.

On Monday the scheduled trial was delayed for a psychiatric report to be prepared with the Crown saying a major issue of the trial would be automatism.

Automatism refers to an act being done involuntarily without control of the mind, or unconsciously.

But on Tuesday the Crown announced the matter would not proceed any further and was being withdrawn.

NSW District Court Judge Warwick Hunt formally dismissed the case set down for five days, telling Ms Teo she was now "free to go and get on with your life".

Mr Ross was president and self-styled "Supreme Commander" of the Comancheros in the 1970s and 1980s, including at the time of the Milperra massacre.

Since leaving prison he had been a volunteer firefighter north of Sydney, but his daughter on Tuesday said her father was forced to stand down from his duties following the crash.

The Director of Public Prosecutions in NSW confirmed the matter had been withdrawn in a statement but would not provide any further comment.

Australian Associated Press