This included "propensity" evidence that Heenan often became aggressive when drunk and claimed he could not remember negative or embarrassing things he had done.
In its decision released in June last year, the Court of Appeal upheld Heenan's appeal, quashed the conviction and ordered a new trial.
The decision was suppressed so as not to prejudice a fair retrial.
On the night of the murder, Heenan had been drinking at his home on Konene St with Mr Newton.
It was the Crown's case Heenan became angry when Mr Newton, who suffered from bipolar disorder, began "conjuring up gods". He approached Mr Newton from behind and stabbed him with either a large carving knife, a Leatherman tool or both. Mr Newton's aorta was severed and he died within minutes.
Heenan had six superficial wounds to his abdomen and one to his arm, which were self-inflicted in an attempt to make it look like Heenan had acted in self-defence.
Mr Newton's mother Charmaine Burnett said yesterday her family were "jubilant the right verdict was made again". "Revisiting the trial again was anguishing and we had to be put through it all over again for the same result. What a waste of taxpayers' money," Mrs Burnett said.
"It triggered for us all of the trauma again and the most difficult part was having to listen to the brutal lies about Raukawa and show no emotion in court, he was never aggressive, he was always known for his gentleness."
Mrs Burnett said Mr Newton left behind four children and his now 10-year-old son asked weekly why Heenan killed his father. "What do you say to your grandson? There's no explanation, no rational reason. It was a cold, calculating murder.
"At least now we can finally start to heal and try and move on, we're relieved it's all over and my son can finally be at peace."