The Solicitor-General could avoid any consequences of John Banks' acquittal but others in Crown Law will be nervous, a law professor says.
The Court of Appeal has cancelled the former ACT leader's retrial on charges of filing false electoral returns during his campaign to be Auckland's mayor.
It said the Crown withheld new evidence about a crucial lunch with Kim Dotcom, amounting to a miscarriage of justice.
Mr Banks told Morning Report the Solicitor-General, Mike Heron QC, should stand aside while an independent investigation is carried out into his involvement in the case.
He said Mr Heron must be held to account for behaviour that was delinquent at best.
"I have been held to account and I have been completely exonerated," he said. "We now need to ask why the Solicitor-General is not being held to account, because he has a lot to answer for."
He said no one in the justice system should be subjected to the treatment he had faced.
"If I hadn't have been tough and resilient with some support and some resources, I would have been burnt at the stake by this jihad."
In its decision yesterday, the Court of Appeal said it was satisfied the Crown's "serious error of process" was an error of judgement rather than misconduct.
Attorney-General Chris Finlayson said he would look into the Court of Appeal decision.
He said, as the Attorney-General, he stayed out of criminal matters, and the Solicitor-General had briefed the job to someone else because it was a criminal case involving a politician.
"Decisions were made by that person on the way in which the case should be conducted and the Court of Appeal has been critical of that aspect of it.
"So [in] broad terms, the Crown carries the can, as it were, but there are matters of concern that Crown Law will be wanting to be look at."
University of Otago law professor Andrew Geddis said Mr Banks would probably be awarded the costs he incurred fighting the charge.
"The fact he had to go back to the Court of Appeal because of the Crown's failure means that he should almost certainly get costs for that part of the courts process.
"And the original Court of Appeal decision - if the evidence had been tendered properly, he probably would have won that, so he's got a fairly strong argument for costs there as well."
Mr Geddis said, if Mr Finlayson's statement was correct, the Solicitor-General may not face any consequences as a result of the acquittal.
"Now if that's true, and there was some sort of Chinese wall keeping the Solicitor-General away from this, well then it may have no particular consequences for him because he just didn't know what was going on."
However, he said, someone in Crown Law would be feeling nervous after the court's judgment.
John Banks' political journey has been both colourful and controversial, rising from local to national politician, becoming a talk show host along the way, and Auckland mayor.