"Ms Taylor, at that time, was working very long hours. She was having to travel a great distance.
"She wasn't someone who was merely sitting idly by at home while her mother was deteriorating.
"She was under an incredible amount of pressure due to her high work commitments."
Keam argued the 12-year jail sentence should be reduced to between eight and nine years.
"The sentencing judge referred to the neglect as 'prolonged', but prolonged is one of those words that can mean quite different things in quite different contexts.
"In a situation where someone is deteriorating due to neglect … really the significant deteriorating was over a period of between 10 and 15 days.
"As opposed to a situation where prolonged could mean a period of months."
Luana and Brian Taylor's lawyers also argued that their sentences, of six years and three months jail and six years jail respectively, were excessive.
Crown lawyer Karen Grau said the sentences were justified because the neglect was so extreme.
She said the defence that Cindy Taylor was overworked had to be contrasted with the fact that her life functioned in all other aspects, including looking after herself, her job, and keeping the shared house clean.
"There don't seem to have been any difficulties for Cindy Taylor to look after her mother.
"She just didn't. She did other things.
"This woman [Ena Dung] was of a sound mind, there was no dementia, she had otherwise been healthy.
"To be lying for 10-15 days in the condition that she was, in my submission that can only be described as prolonged suffering."
Grau said that Luana and Brian Taylor must have deliberately closed their eyes to the situation, as it was a small house and the smell from Ena Dung was very bad.
The Court of Appeal judges have reserved their decision.
Ena Lai Dung's body was discovered by emergency services on January 16 2015, at a south Auckland home.
She was found in bed on a tarpaulin, lying in her own excrement, naked from the waist down and surrounded by flies. She weighed just 29kg when she died.
At the 2016 trial a paramedic who found Dung described her as looking like a "scarecrow".
Dung had 14 broken ribs and sternum but no medical assistance was sought. She was left on a plastic sheet in her own urine and faeces, causing her to suffer chemical burns, and was given no pain relief.
She had several bed sores, one of which had penetrated through to the bone, and another which was gangrenous.
At the time of her death the 76-year-old had gone four to five days without water, and up to 15 days without food, during the height of summer.
Failing to protect a vulnerable adult is a relatively new charge in the New Zealand legal system, and Dung's case was believed to be the first of its kind to go before our courts.
