Police outlined a concerning series of events where Casey harassed the woman.
The victim, a woman in her 50s who lives alone, had a brief friendship with Casey but when that ended he began targeting her.
On August 17 this year, police were called to her Amberley house because Casey was refusing to leave.
Officers trespassed him from there for two years.
But nine days later, he sneaked back at night to fill the petrol tank of her with 60 litres of fresh water.
It cost her $173 to get a mechanic to drain it.
On August 31, Casey returned to pour motor oil in her petrol tank, amounting to a further $217 repair bill.
A fortnight later, police were called after the woman saw Casey on her property at 3am, peering in the windows, and turning off her power at the outside mains box.
"This caused the victim to be terrified that she was going to be attacked in her home," a police summary of the facts said.
The next night, he came back and poured dry ready-mix concrete into the petrol tank, and into her engine, which set hard, rendering the car "immobile and irreparable".
Police caught him fleeing at speed on State Highway One and arrested him.
Defence counsel Kirsty May today said Casey was extremely remorseful and "very aware" of the impact his offending which amounted to a "betrayal of trust".
He has independently engaged with counselling and resumed his anxiety medication.
Judge Paul Strettell said it was an "unusual" case which must have had a significant emotional and psychological impact on the victim.
The judge said that in some cases this type of offending would have resulted in a jail term.
But given Casey's troubled background, his remorse, early guilty plea, and reparation paid, Judge Strettell sentenced him to five months of community detention.
It came with conditions that he abide by a 7pm - 6am curfew, that he is subject to nine months of intensive supervision and to complete a stopping violence programme and to undergo counselling.
