Alzheimer's is a pretty terrible, debilitating disease. Those afflicted are often not in control of their actions. Recognizing this, California already has a rule that Alzheimer's patients in institutional facilities like nursing homes aren't responsible for injuries they inflict on caregivers.
What about in-home caregivers? They had no special protection until Monday, when the California Supreme Court ruled 7-2 that, yes, the rule also applies to them under the doctrine of assumption of risk.
But really, this case presents a legislative, not a judicial, problem.