She tried to flee, but he grabbed a knife and stabbed her in the chest, arms and legs before he poured the fuel over her body. It made her skin slippery, and she escaped his grip.

Dr Jay — who has since become a domestic violence awareness advocate — fled the house, screaming, to get help from her neighbours. Within hours, her attacker would be dead.

Mr Lambert had fled the home after the attack and driven north before he called Dr Jay's phone and asked the paramedic who answered, “how is she?” and said “I didn’t mean to do it".

In a flurry of phone calls and text messages to police and family members, Mr Lambert said he'd stabbed his girlfriend and tried to set her alight, and he threatened self-harm.

Police eventually confronted Mr Lambert as he brandished a knife during a tense, six-minute stand-off next to the Pacific Highway on the NSW Mid-North Coast after a pursuit.

Officers shot him dead when he lunged towards them with the knife.

Those officers had no choice but to pull the trigger on Mr Lambert given his actions, an inquest into his death found on Friday.

The pair's brief relationship ended in bloody tragedy but had started on a dating app a few months earlier.

Dr Jay, a trainee obstetrician and gynaecologist, met Mr Lambert, a banker from Kogarah in Sydney's south, on Tinder and the pair dated for less than two months.

Their long-distance relationship soured and Dr Jay ended it after she began to feel overwhelmed by his increasingly possessive and controlling behaviour.

He began to emotionally manipulate Dr Jay, making her feel she couldn't reject him. He threatened self-harm and suicide, claimed to have mental illnesses and feigned the deaths of family members.

It reflected a pattern of intimate partner violence against multiple past girlfriends over many years, Acting NSW Coroner Teresa O'Sullivan said in her findings.

"Sometimes he would contact family members of romantic partners and make threats of harm or created false identities to stalk partners.

"He would claim diagnoses of various psychological disorders to excuse his behaviour, implying that he suffered from a dissociative or multiple personality disorder."

He sometimes referred to himself as “bad Paul” or “evil Paul”. At one stage, Mr Lambert claimed to have nine personalities.

Mr Lambert was also the subject of 10 apprehended domestic violence orders relating to five women, including Dr Jay, between 2003 and 2016. He had breached those orders on three occasions.

The month before the attack, Dr Jay confided to a friend that she was scared and felt Mr Lambert was emotionally blackmailing her with his threats of self-harm. She reported him to police.

        "The techniques of manipulation may seem obvious in retrospect but they were subtle and insidious at the time, involving layers of escalating emotional abuse," the coroner said.