"Two-and-a-half years won't last long, mate," he called out.
Judge Hix asked him to "conduct yourself in a respectful way".
Hart carried on anyway, telling the couple: "Wait till I get out. I know where you live. I'll get out in two-and-a-half years and I'll see you then."
He started calling out racial slurs before Judge Hix had court escort staff remove him from the court and back to the holding cells where the shouting continued.
Victims had spoken of physical injuries and post-traumatic stress in their victim impact statements, which were not read out in court.
Judge Hix suppressed their names but declined an application by defence counsel Carol Morgan to suppress Hart's name.
He had admitted charges of intentionally damaging two vehicles, intentionally injuring one person, two of assault with intent to injure, assaults with a rock and a chair as a weapon, and the four protection order breaches.
The pair remained calm and stayed in court while Hart made his threats and after he was taken out, they watched the sentencing go ahead.
Judge Hix noted Hart's behaviour and threats and described it in his sentencing remarks so that it would be before the Parole Board when Hart is eventually considered for parole.
"I am concerned about his behaviour in court today," he said. "It is my view that it is not appropriate to depart from the sentencing indication. The matter of how he conducted himself in court today can be dealt with through other vehicles or through the Parole Board when the time comes."
That comment appeared to be a suggestion that the police might consider charging Hart with threatening behaviour.
He also ordered Hart eventually to pay $800 - the insurance excesses on the two cars that he damaged.
The two people in court will be placed on the victims' notification register so that they are informed when Hart is released.
Hart had accepted a sentencing indication -- a hearing that lets offenders know what their sentence would be if they pleaded guilty. The hearings are not allowed to be reported until the sentencing takes place.