A barrister says a coroner's ruling that an assault of a west Auckland schoolboy was a direct contributor to his death four years ago isn't enough to trigger a re-try of the offenders.
Two brothers escaped unpunished for the football field assault because 15-year-old Stephen Dudley had a pre-existing heart condition.
But Grant Illingworth QC says fresh evidence is usually needed for a further trial to be held.
"The coroner's role does not permit the coroner to fix blame and the coroner hasn't purported to do that. What the coroner has done is to say that the assault that took place was a significant cause of the death.
"If there was some compelling fresh evidence then it is possible sometimes for a further trial to be held on a more serious charge, but it does depend on there being substantial new evidence which justifies a review of the situation."
Stephen's parents are calling for the re-opening of the criminal case into his death following the release of the coroner's findings yesterday.
Dudley family spokesperson Ruth Money told The AM Show the coroner ruling is grounds enough for a retrial.
"We've now had the cause of death determined as being that physical assault. People have called this a schoolyard fight; there was no fight, this was determined - Stephen didn't punch back, there was no fighting. This was a thug coming in from nowhere, assaulting a much smaller boy at a rugby practice."
Police have acknowledged the coroner's findings, saying his death was "thoroughly investigated" by officers at the time.
Following the report, Waitemata Police District Commander Tusha Penny says police may now look into the case again to see if any parts of their investigation or prosecution need to be revisited.