As you noted, the personal auto policy (PAP) first requires the insured to be legally responsible for any bodily injury or property damage in order for the policy to pay for any damages.

However, this legal responsibility does not necessarily have to be based on the negligence of the insured. It is possible that such responsibility could be established through strict liability based on state law. For example, if the state legislature has passed a law declaring that a driver must safely operate or control his vehicle at all times, a driver who crashes into another auto, regardless of the reason (e.g. a heart attack), could be held strictly liable for any resulting injuries (and thus, have the benefit of insurance coverage).

Of course, the courts would have to decide this point, that is, whether the strict liability law would apply in a situation such as you describe in your question. The supreme court of Ohio has not finally decided this particular issue. However, you should be aware that a court of common pleas in Mahoning county ( Ohio ) has ruled that strict liability is the proper standard of review under which the sudden loss of consciousness cases should be examined. In Canis v. Fleps, 88 CV 631 (1992), a driver suffered a stroke and collided with another driver which resulted in serious injuries to that other driver and the judge ruled that the defendant was liable as a matter of law for violating a statute regulating the operation of motor vehicles (regardless of the stroke). Even though this particular decision was not appealed, it is possible that the Ohio supreme court could eventually review a case with similar facts and circumstances and make the Canis decision the law of Ohio .

As of now, however, negligence is still the standard of review in Ohio and this standard gives an insurer grounds to deny coverage under the PAP (note also that this is the legal viewpoint in a majority of states). Under the negligence standard, where the driver of an auto is suddenly stricken by a heart attack that renders him unconscious, an attack that he has no reason to anticipate and that makes him incapable of controlling his car, that driver is not held liable for such loss of control. The driver is not negligent unless he had a reason to anticipate or foresee the heart attack and its consequences. So absent negligence, the driver is not legally responsible for the injuries; and if he is not legally responsible, the insuring agreement of the PAP does not apply.