According to Judge Peter Hobbs, the kidnapping was a "case of mistaken identity".
The victim, a 24-year-old doctor, was preparing to take a nap in the back seat of her car outside the hospital before her shift.
Punchihewa and two co-offenders believed she was somebody else, waiting to meet a man they knew through gang connections.
They opened her car door and got into the vehicle, making reference to the man and asking for her car keys, Judge Hobbs said.
The victim tried to make a run for it but was caught, put in a chokehold and dragged to Punchihewa's car. The co-offenders punched her in the head and subdued her before the group drove to another area with the victim.
"The victim continued to try and explain to you and your co-offenders that you had the wrong person . . . the victim was convinced you meant to kill her," the judge said.
According to a victim impact statement read in court, the woman said the group talked about a gun they had, and a grave they had dug in preparation.
She took the opportunity to make a break for it again when a phone belonging to one of the co-offenders rang. She managed to escape and was found a short time later by police who had been called about the incident.
Punchihewa and his co-offenders travelled back to the woman's car and used her keys to take her vehicle. It was found by police a few hours later.
Later that night, Punchihewa called police and reported his car had been stolen.
A search warrant carried out two days later at his home uncovered 49 rounds of ammunition in his bedroom.
"While remanded in custody you were transferred to hospital after an alleged assault in prison," Judge Hobbs said.
The prisoner was being watched by two security officers, but he was allowed to use the toilet in private while handcuffed to a rail.
Punchihewa managed to free himself from the handcuffs and his electronic monitoring bracelet and flee the hospital, pushing a security officer out of his way in the process.
He remained on the run until late December last year.
"In explanation, you said you woke up in a hospital thinking your organs were about to be harvested and escaped to protect your life."
During sentencing, Judge Hobbs noted Punchihewa, a father of three young children, had received counselling while on bail for methamphetamine use.
The judge also referred to reports detailing Punchihewa's "traumatic" experiences in Sri Lanka, including an incident where he narrowly avoided being harmed in a fatal bus bombing, in which a friend of his was killed.
Judge Hobbs also referred to the impact of the offending on the victim.
In her statement, the victim said she had suffered bruising and grazing, had some of her hair pulled out and had a subconjunctival haemorrhage and a tender jaw.
She had to take time off work and see a counsellor and had to pay to replace her items stolen in the kidnapping.
"I was really scared that I was going to be beaten up and left somewhere . . . no one would have noticed if I hadn't come home that night," she said.
"When they talked about the grave they had dug . . . I thought I was going to die."
She now suffers flashbacks when driving to work and has panic attacks at night.
Judge Hobbs sentenced Punchihewa to two years and three months in prison.
He has two minor previous convictions.
