If someone hits you because they had a seizure, doesn't their insurance company still have to pay for the damage?

The previous attorney from Connecticut is correct.

The difficulty is that you will probably need to file suit and engage in discovery in order to learn whether the driver had reason to know of the possibility of a seizure.

I will also agree with the attorney from Connecticut. With the above information in mind you need to contact a lawyer in your area to discuss this further. 

It is not a slam-dunk. 

However, the driver knowing or should know that they have a disorder may have such liability that it could be covered or otherwise pursued.

Insurance companies are required to pay out money to people where their insured causes property and/or bodily injury to people while the policy is in effect.  For the damages to be covered, there must be an accident where the insurance company's insured is at fault.  In this case, the insured had a seizure.  a seizure is generally a involuntary action as opposed to an action that can be controlled.  Therefore, if the involuntary action proximately caused the accident, then the insurance company may not have to cover the claim and the insured may not be at fault for the damages.  However, if the insured was aware of the possibility that they would suffer the seizure and decided to drive anyway, then you should be compensated as the driver knew or should have know that they could injure/damage another driver if they drove.