But last December the company pleaded guilty a week into a hearing in the New Plymouth District Court.
Judge Jim Large today fined Idea Services $425,000 and awarded costs of $52,622 to the prosecutor, WorkSafe New Zealand.
He suppressed all details of the woman's family and their victim impact statements at their request, awarding them $75,000 in reparations – a total punishment of $552,622.
Judge Large said Idea Services failed to implement a care plan, didn't assess the level of support needed for the victim to use a bath, and information carers needed was not available to them.
He said the carers had no guidance on how to balance the victim's right to privacy against their duty to ensure her safety.
"Respecting [her] privacy was an important aspect in caring for her but when it came to protecting her from harm [her] right to privacy had to yield to ensure her safety."
WorkSafe's lawyer Trina Williams McIlroy earlier told the court Idea Services failed to properly address the risks associated with bathing the victim, who had a dual diagnosis of intellectual disability and bipolar disorder.
"[She] was a vulnerable service user who required 24-hour one-on-one support from the defendant, including while bathing."
Williams McIlroy said the victim's increasing health needs had seen her recently moved from shared accommodation to the Waitara address for one-on-one care.
"[Her] array of mental and physical conditions, symptoms, complications and hazards ... included choking, loss of consciousness, possible seizures and heart failure. The defendant was aware or ought to have been aware of these conditions and in particular [her] propensity to become fatigued, dizzy and lose consciousness."
Idea Services' lawyer Garth Gallaway said carers knew she needed 24-hour supervision but she'd successfully had baths by herself the week before.
"The way that it was interpreted was someone in the bathroom from time to time but not at all times, because she was capable of getting herself in and out of the bath depending on what state she was in."
Gallaway said Idea Services had now banned any unsupervised baths.
He said other improvements had also been implemented, including a new electronic system for carers to record and pass on patient information in real time between shifts.
It is the second time Idea Services has been convicted over a patient drowning in a bath.
The company had to pay $153,500 after 15-year-old Nathan Booker drowned in a bath at its Woburn Family Support Centre in Palmerston North on January 10, 2014.
In that case, Judge Jennifer Binns said deficient training and uncertainty around procedures and policies made the death not an accident but totally preventable.
It was fined $63,500 and ordered to pay $90,000 to the family.
Garth Gallaway said the Waitara case was not such a significant failure of care, as the victim was not as severely disabled as in the Palmerston North case.
However, the Health and Safety at Work Act has since been updated to allow for much higher fines, and for costs to be awarded to prosecuting agencies.
