Why would the coroner rule a natural death for my mother who was found dead on the floor with a stove on top of her?

M2M is absolutely right about cause of death findings. My friend's father had a life insurance policy that only paid for accidental death. He had heart attack and fell, breaking his neck and dying as a result. Insurance said heart attack was cause of death, not neck. No payout. My sister (who works in insurance) said that for any elderly person or one with medical issues that can be listed as cause of death such a policy will almost never pay out short of falling over something not related to physical infirmity and breaking one's neck. If the stove was pulled over onto mom BY HERSELF because she had a heart attack or broke a hip or had a stroke and she grabbed it going down, a coroner is going to rule that the preceding event is what caused (proximate) death.

If she suffered a heart attack and grabbed the stove on the way down then the heart attack would be the cause of death, hence natural causes.

As a police officer I investigated a car crash, single vehicle into a pole, where it was determined that the person suffered a heart attack before the collision and it was labeled natural causes.