Less than 30 minutes later, the defendant was driving south on State Highway 1 towards Balclutha.
As the road veered left, Haggart did not.
His car travelled along the water table before it came to a stop.
Haggart's efforts to get going only resulted in his tyres continuously spinning.
A member of the public withdrew the vehicle's keys and called emergency services.
''[She] was really trying to help you,'' Judge John Strettell said.
But Haggart was in no mood to be helped.
''The defendant became disgruntled by the victim calling police and went to grab his keys from the victim,'' a police summary said.
''[He] grabbed the victim's arms and wrists and a struggle caused the victim to fall to the ground.''
The farcical scene ended when another member of public restrained Haggart until officers arrived.
A breath test gave a reading of 774mcg - more than three times the legal limit of 250mcg.
He had no memory of the incident, the court heard.
Counsel Anne Stevens said her client had no convictions since 2011 and two years before that he had suffered a severe head injury in an accident, after which he was admitted to a rehabilitation facility.
Judge Strettell said the defendant's brain trauma ''muddied the waters'' in his assessment of culpability.
It was not clear, he said, how much the alcohol contributed to Haggart's erratic behaviour and how much came from his pre-existing issues.
He accepted the defendant was remorseful.
''Perhaps on another day you would have not acted in the way you had, but regrettably this happened and you are responsible for it,'' the judge said.
Haggart was sentenced to nine months' intensive supervision, 100 hours' community work and was banned from driving for eight months.
He was also ordered to pay the victim of the assault $2350 to cover her loss of earnings while recovering from a wrist injury.
