Today, prosecutor Jasper Rhodes described Epenisa's condition declining in the months before his death in 2016.
Epenisa, a stroke victim, had incontinence and difficulty talking, the court was told.
Rhodes said Li in 2015 was providing adequate care for her husband, who'd just been discharged from hospital.
"He appeared to be unable to speak but was otherwise in relatively good health."
But Rhodes said between that point and Epenisa's death, the quality of care declined and Li prevented other people from helping her husband.
The prosecutor said Li lied to evade unwanted scrutiny and was being paid as Li's sole carer at the Tongan community-operated home in Māngere.
Rhodes said one such lie involved Li telling a friend of Epenisa's he was doped up on new medication, needed rest and was unable to see visitors.
Some friends would probably not have helped the unwell man go to the toilet, partly for cultural reasons, Rhodes said.
"But that doesn't mean they wouldn't have helped at all. At the least they could have helped around the house."
Rhodes said the most dramatic decline happened in about the month before Epenisa died.
The smell in Epenisa's room worsened, and stemmed from unwashed clothes, human waste and rotten skin, Rhodes said.
Rhodes said someone raised concerns about the smell and suggested Epenisa go to the doctor but Li responded: "Don't worry about him, because this kind of sickness is just like that."
The Crown suggested Li became grossly negligent and failed to do anything to save her husband's life.
The prosecutor said Epenisa had been a sociable man, who enjoyed church events and a local men's group.
"Even if you accept he didn't want to see anyone, the point is, they were available to help Ms Li if she asked."
Rhodes said Epenisa was frequently left alone for spans of seven or eight hours with a few snacks and a bottle to urinate in.
During these episodes, Epenisa would likely have had no choice but to defecate on himself, Rhodes added.
"If things were going to go badly for Mr Epenisa, they were going to go badly relatively quickly."
Jurors heard Epenisa's final visit to a Hillsborough doctor was in January 2016, nine months before his death.
Rhodes said Li could not defend herself from the manslaughter charge by suggesting Epenisa demanded not to be helped.
"Ultimately, he did not have a choice."
Epenisa's daughter last week said her father's moods changed after two strokes incapacitated him.
The daughter claimed her dad started yelling and swearing more after the strokes.
The trial before Justice Edwin Wylie and the jury continues.
