> That’s not about cost-savings, it’s about avoiding false positives that make no sense in clinical context but raise flags that must be chased down.

Unfortunately the rule doesn't apply in this case. Your "smart" toilet is not trying to diagnose problems. It is trying to infer which ads you will click on the most, to make money for a surveillance company. A toilet that has a handful of true positives, a huge number of false ones, and doesn't kill too many people is pure win: surveillance and pharma both make money, and it's very hard for a consumer to tell if he never had X disease, or if buying the medicine prevented his X disease.