She was sentenced to life in prison in April 2012.
A Henry Bennett Centre staff member, whose name is suppressed, told the inquest there was a history of arguing between Morris and Ms White.
Morris, a voluntary inpatient at HBC, argued that Ms White and her boyfriend had "made her life miserable and spread rumours that she was a mental health patient".
He said her state worsened when her five-month-old son was taken into Child, Youth and Family care, not long before she killed Ms White.
"At this point Ms Morris ...made direct threats to the lives of her two neighbours and due to these threats I told her I was unable to discharge her," said the staff member.
Morris' anger had reached a "critical level" but she asked to take a cigarette break before she was sedated.
She instead scaled a wall and escaped the facility and headed to her Blackburn St flat.
Asked whether a DHB duty authorized officer should have been sent to Morris' home, given the threats she had made, or whether it would have helped, the staff member answered: "I honestly do not know".
The inquest heard how HBC staff called police at least three times between 10.30am and 12pm and sent a fax advising that Morris had fled.
Sergeant Murray Stapp said Morris went to a neighbour's house, where she had a cup of tea prior to the attack.
The neighbour contacted the HBC telling them where Morris was but police could not find her.
She called police when she saw Morris in blood-stained clothes not long after.
The inquest before Coroner Peter Ryan is set down until Friday with 14 witnesses to give evidence.
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