Gordon Kriese, 82, died last July after an altercation with another patient in the hospital's dementia ward.
RCMP said the incident should not be described as an unprovoked attack, and the other man involved had no criminal intent to harm Kriese.
Island Health spokesperson Sarah Plank said an internal report also found the incident could not have been prevented.
"According to the review, neither patient was considered a risk for violence and placement in a shared room was an appropriate clinical decision, based on the assessments by staff," Plank said.
Kriese's daughter Laura Chafe does not agree with that conclusion.
She said she doesn't fault police for not recommending charges, but Island Health should have known the other man was violent and should have been in a more secure ward.
"It should never have happened ... I mean, what were they even thinking. He should never have been in a palliative care wing," said Chafe.
"He should have been under lock-down on the third floor. They should not have moved my father into that room with him."
Chafe said she plans to file a formal complaint with the provincial patient quality review board.
Correction : An earlier version of this article misrepresented how the patient at Cowichan District Hospital died. In fact, the patient died following an altercation with another patient.
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