He left school at 12 and began using illicit substances including methamphetamine.
Tiddy fathered a child with an older woman when he was just 14 and began dealing drugs to keep them afloat.
His visa was revoked, he was deported to New Zealand in 2017 and within months, his crimes continued.
Because of his substance abuse and high-risk behaviour, something catastrophic was “always on the cards”, counsel Andrew Dawson said.
The court heard Tiddy had never held a driving licence.
On January 23 he was driving Broad’s Honda Accord around Dunedin.
He was seen hitting a kerb as he parked at a fast-food restaurant and witnesses later reported him tailgating and swerving into oncoming traffic.
About 11.30pm, he entered Waikouaiti where there was a temporary 30kmh speed limit because of road works.
Tiddy lost control on gravel, hit a speed sign, rolled the vehicle and slammed into a tree.
Broad died instantly and Tiddy was hospitalised with broken ribs and a broken collarbone.
Neither Broad nor Tiddy were wearing a seatbelt, court documents said.
An app on Broad’s cell phone revealed Tiddy hit speeds of 158km/h during the trip.
In hospital he gave a blood-alcohol reading of 140mg. THC - the active constituent of cannabis - was also detected.
“This was an extended period of driving that disregarded virtually every rule designed to keep road users safe,” Justice Dunningham said.
The victim’s daughter Tara Broad was 37 weeks pregnant at the time of the crash and told the court she was heartbroken her child had missed out on a relationship with their grandmother.
Some of the family were further traumatised by a restorative justice meeting with Tiddy in June.
“You walked into that room, head down, cursing, swearing and kicking furniture . . . very aggressive,” said Tara Broad.
“You didn’t even look at us.”
Tiddy had told them he always drove drunk but would refrain in the future.
“If anything, it added to our grief,” Tara Broad said of the meeting.
The victim’s son Casey Antill said Tiddy’s actions had devastated the family.
Broad and her son had been rebuilding their relationship before the crash and were employed at the meat works together.
“I’m now having to look at a future without my beautiful, quirky mother,” he said. “She was a one-off and I loved her.”
Crown prosecutor Richard Smith highlighted Tiddy’s history of reckless driving and the fact he was breaching his bail curfew at the time of the crash.
He was assessed at high risk of reoffending.
Judge Dunningham imposed a minimum non-parole period of two years and banned Tiddy from driving for five.
Dunedin downfall
Nov 2017: Tiddy is caught drink-driving in Dunedin just months after being deported
Dec 2018: Despite having no licence, he is seen doing a burnout in his partner’s car before fleeing police on foot
May 2019: Tiddy takes aunt’s car without her permission
Jun 2020: He is sentenced to intensive supervision, community detention and community work after forcing himself on three women
Oct 2020: Tiddy does doughnuts on a playcentre field then crashes into a police car
Nov 2022: Police turn up to a house for a welfare check on a woman to find him wielding a metal pole as a weapon
Jan 2023: While on bail for the weapons offence, Tiddy crashes, killing Katherine Broad
