A WA coroner says it is impossible to determine whether the life of a wheelchair-bound man who died from asphyxiation could have been saved had a carer attended his house at the usual time.
Leslie Troy Ovens, 32, was living independently in a purpose-built house in Ellenbrook with his care provided by Cam Can and Associates when he fell from his wheelchair and suffocated in July 2013.
Mr Ovens was aged nine when he was diagnosed with Friedreich's ataxia, a disease that causes progressive damage to the nerves often leading to a loss of strength and co-ordination, and required an electric wheelchair by the time he was 15.
Carers routinely visited Mr Ovens twice a day, in the morning and night, but no one showed up at 8pm to put him to bed as usual because a relief care co-ordinator hadn't rostered anyone on and didn't provide the usual co-ordinator with a draft roster indicating gaps.
One of Mr Ovens' carers who wasn't rostered on that day visited at 5pm to give him some drinking straws, but the next carer didn't arrive until the following day.
"It is not the case a rostered carer failed to attend," Deputy State Coroner Evelyn Vicker said in findings released on Monday.
"There was no carer rostered."
Ms Vicker said there was a lack of an appropriate and clear handover system for communicating rosters, which should be shared with people being cared for.
"There was no system in place to ensure the lack of attendance of a carer would be detected in a timely manner if the deceased was incapacitated in some way," she said.
Ms Vicker said it was impossible to determine with certainty that a carer attending at 8pm would have been able to save the deceased's life.
"This was a terrible death for anyone," she said.
"And the lack of dignity so important for someone such as the deceased, who valued his independence so much, is magnified by the knowledge he must have been in that position for at least 12 hours.
"For the short time in which he remained aware of his circumstances, he must have felt truly abandoned by those assigned to care for him."