The defence sets the reform agenda for judge-made law, the Director of Public Prosecutions told the prosecutors' conference on Saturday.
James Hamilton said judges do not set the agenda when it comes to judge-made law. Courts only make decisions in the cases that come before them and the defendants have the right to bring points of law on appeal again and again.
"If the defence eventually win a particular legal argument, the court can only change the law back again if a suitable case comes before it."
At the moment the prosecution has no input into this process, and he welcomed the proposal in the Criminal Justice Bill now before the Oireachtas that would allow the prosecution appeal on a point of law, without prejudicing a person's acquittal.
He said the present system in the Court of Criminal Appeal, where three judges, two from the High Court and one from the Supreme Court, are allocated to it on a rotating basis, makes it difficult for this court to establish a consistent body of case law.
Sir Alisdair Fraser, the Director of Public Prosecutions for Northern Ireland, said the public prosecution service there had undergone root and branch reform since the Good Friday Agreement.
This involved bringing all prosecutions, including those previously undertaken by the police, under the service, which was staffed by trained lawyers. All staff, including non-legal staff, will have specialist training, including human rights training.
Police will no longer prosecute. They will just conduct the investigation, he said.
Referring to the issue of giving reasons why certain prosecutions do not go ahead, he said reasons were given, albeit in general terms, like an insufficiency of evidence.
The service recognised there may be some exceptional cases, where death may have been caused by the conduct of agents of the state, where more might be required, and he drew attention to the relevant section of the new Code for Prosecutors.
It states: "Subject to compelling grounds for not giving reasons, including duties under the Human Rights Act, the Prosecution Service accepts that in such cases it will be in the public interest to reassure a concerned public, including the families of victims, that the rule of law has been respected, by the provision of a reasonable explanation."