The bail checks formed one part of their 120-page complaint to the Independent Police Conduct Authority about the way their son's case was handled by police.
The IPCA found while there were some issues, there was nothing in the handling of the case that amounted to misconduct.
Police also stand by their actions but Counties Manukau area prevention manager Inspector Colin Higson has since apologised for some of the bail checks.
The apology isn't, however, enough for the family, with the teen's parents saying the experience has damaged their trust in the system.
"All we have wanted is a full apology for all of the pain and damage that they caused us and an acknowledgment that their actions were inappropriate; that there was never a focus on getting to the truth, only on beating us down."
The teen himself also believes justice is yet to be served and wants to see the complainants in the case prosecuted for assault because of the head injury he suffered.
The bail checks
The teenager was arrested and charged after he turned 18.
Despite having no prior convictions the then secondary school student was bailed with a 24-hour curfew to the home he shared with his parents and younger siblings.
A week before the teenager was due to enter a plea, his lawyer applied for a variation to the bail conditions to allow him to play sport.
Despite no bail checks before this point, two days after the bail variation application police began enforcing the 24-hour curfew by arriving at the teen's home at random times.
Police came to his house six times - five for bail checks - within a 19-hour period on the day and night before the plea hearing. They carried out 30 bail checks in 22 days across two months, including 12 times between 10pm and 4.30am.
In an affidavit to the court requesting removal of the curfew, the mother described the bail checks as invasive and destructive for their other children.
"I am concerned that ongoing early-morning checks will not only significantly impact on our other children's academic progress but also on their physical and mental wellbeing," she wrote.
At the plea hearing, moved to the District Court because of the seriousness of the charges, the bail conditions were amended by a judge to "not to be found outside the residence between 7pm and 7am".
Contrary to this, six days later the teen's younger sister was woken at 4.19am by police shining a torch in her bedroom window.
There were three other times after the judge's directive that police bail-checked the teen at home, including on another night before the young man was due to attend court again.
The IPCA found no fault with police for the bail checks, saying police needed to carry them out at random and unsociable hours.
However, the family has since received an apology from Inspector Higson for the four bail checks that "should not have occurred" after the judge's directive.
"The reason for the checks being made appears to be one of simple misunderstanding of the reverse onus taken by the court," Higson wrote.
"These type of checks are relatively unusual and without justifying their actions, I can understand how this misunderstanding could have been made by the staff members concerned."
The father said it felt as if police were using the bail checks as a weapon to break down his son.
The young man told Open Justice the overnight bail checks were intimidating and he believed the continuous sleep interruptions delayed his recovery from the concussion.
Inconsistent statements
In their IPCA complaint, the parents raised concerns about the changing statements of the complainant and his associates, as well as the identification of their son.
The conflicting statements prompted the Crown to drop the assault with a weapon charge and reduced grievous bodily harm to wounding with reckless disregard for the safety of others.
Seven months after the arrest, police took a statement from a key witness - a mutual friend of the teenager and one of the associates.
It revealed the complainant and his two friends had briefly met the teenager through the mutual friend on the night of the attack to buy "weed", and one admitted they started the fight with the intention of beating up the teenager.
It meant they lied to police by saying they had never met the teen before the attack and that the teenager was the aggressor who ambushed them.
In a memorandum to the court, the prosecution said there were significant issues with the credibility of the complainant and his associates.
The possibility the teen was acting in self-defence could not be excluded.
Because of the lack of reliable evidence, the prosecution said it could not prove the force used by the teen was not reasonable in the circumstances.
The memo invited the court to dismiss the remaining charge which it did, almost a year after the altercation.
The IPCA agreed there were issues with the police formal identification process, "where inconsistencies in the [complainants'] statements went unnoticed".
"We also believe police could have made attempts to get a statement from [the mutual friend] earlier."
But it did not consider these issues amounted to misconduct or neglect of duty.
It said police considered whether to charge the complainant and his associates for perverting the course of justice.
But doing so could have had repercussions for the teenager related to the "drug deal".
The father said his son's neurodiversity made him socially awkward and he had supplied weed to win friends, something he no longer does.
A police spokesperson said the family's concerns were carefully considered in detail by the IPCA, which found there was no misconduct or neglect of duty by the officers involved in this case.
"We acknowledge the IPCA's findings and we maintain that the investigation was handled appropriately by the police staff involved."
