Lawyer Eugene McGee hit and killed cyclist Ian Humphrey on the Kapunda Road, in 2003.
He was fined for driving without due care.
In 2011, Attorney-General John Rau said he had received legal advice no further action could be taken against the prominent lawyer.
Opposition MP Vickie Chapman told Parliament Mr Rau should have referred Mr McGee to the Legal Practitioners Disciplinary Tribunal.
"He should act on this and clearly the investigation of the Opposition, with the legal assessment of this, was that there was a clear legal authority to lay the charges before the tribunal," she said.
"The Attorney-General's position was that he considered he didn't, we're not satisfied with that."
Ms Chapman was critical of the Attorney-General for the Government's failure to introduce promised legislation which would avoid such legal impediments in any future situation.
She said 7,000 South Australians had signed a petition demanding action over the McGee legal case.
Attorney-General John Rau said the promised legislative changes were close.
He said the delay was due to the need to consult.
"Nobody is more disappointed than I am and I speak to my staff about this frequently. In fact I've told them my cat is sick of hearing about the Legal Practitioners Act because I even talk to my cat about it. It is getting to the point where I'm getting very angry about how long it is taking, but it will be here it will be here by the beginning of March," he said.
Independent Senator Nick Xenophon said the delay in referring the McGee case to the disciplinary tribunal was unacceptable.
"I think the Attorney-General is talking hogwash when it comes to that. He has the absolute discretion and the power to refer Eugene McGee to the disciplinary tribunal," he said.
"He needs to explain face-to-face to Di Gilcrist-Humphrey (wife of the victim) why he's not doing this."