The Herald can reveal that moments before the fatal assault, Eli had fired water pellets from a water pistol-style gun out the window at people on the street.
He was allegedly attacked by one of those people when the car he was in stopped at traffic lights.
A 30-year-old Bulls man has been charged with causing the death of Holtz by an unlawful act - namely assault - thereby committing manslaughter.
He appeared in the Auckland District Court briefly this morning and was granted interim name suppression.
Eli's family did not want to speak about the specifics of his death but spoke to the Herald to pay tribute to the teen.
It is understood Eli had never been in trouble with the law before his death.
His eldest sister, Chanelle Armstrong, said her family was finding it really tough to deal with the sudden passing of the much-loved son, brother, uncle, boyfriend and friend.
"It is something we never expected to happen, especially to someone who was just so gentle and kind," she said.
"My brother died and now there is a man who is going to face really serious criminal charges because of an incident that happened in the blink of an eye.
"That is going to affect his life forever so there are no winners in this situation.
"Nothing can be done to bring back my brother. It is just a tragedy everywhere."
Armstrong described her brother as a fantastic kid who was always positive to be around.
"He had this huge beautiful smile and he was really kind-hearted, generous and gentle."
Eli was one of seven children who were born and raised in Whangarei.
He completed his final year at Tikipunga High School last year.
"He loved volleyball and was in the volleyball team at school, as well as basketball. He loved his sports," Armstrong said.
"He was an 18-year-old so he loved hanging out with his mates, playing XBox with his brothers and hanging out with his nieces and nephews.
"He had lots of nieces and nephews and was a fantastic uncle. He always had time for them and was always one of their favourites because he would genuinely give them full attention and get down on their level and play with them.
"The favourite memories I have of him are seeing him as an uncle, just because he embodied everything we loved about Eli."
Eli had enrolled in NorthTec for the 2018 year and was planning to study drama.
"He always wanted to be an actor and told us about it a lot," Armstrong said.
"He was pretty funny but he wasn't a huge extrovert. He definitely had a way about him and people were just naturally drawn to him.
"This was the first time he decided for himself to do something about it, so it was kind of hard for us to know this wouldn't happen as we were so excited for him."
She said Eli's death had thrown the close-knit family, but they were happy to have spent time with him in his final hours.
"We are happy that he is home with us now, that we had some time to be with him before he died and when it was time for him to pass, that we were all there with him.
"I think amongst all of that, it has been really humbling to see the outpouring of love and support from our community, family and friends.
"I think that is a real testament to the person that Eli was."
Armstrong said the family were now focused on providing Eli with "the funeral he deserves for the life that he lived".
"We loved our boy and right now we just want to focus on him, have some time with him and send him off properly.
"This is our process and this is what we have to do before we focus on anything else."
Tikipunga High School principal Alec Solomon said the school plans to work closely with the students and staff as they mourn Eli's passing over the coming days.
"We acknowledge this is a very sad time for his family, and for all of us who knew him well at school."
Detective Inspector Scott Beard could not comment on the specifics of Eli's death as the matter was before the courts.
"The death of Eli Holtz is a tragedy," he said.
"No parent should have to bury their own child, and our deepest sympathies are with them as they grieve the loss of a much-loved son and brother."
