Seems to me that a medical explanation could be an affirmative defense in a case like this against criminal or motor vehicle charges, since it would eliminate the element of willfulness or recklessness. Insanity defenses result in people being confined for treatment, not as punishment. In the case of a brain tumor, the standard treatment is different from that for mental illness.
The person struck by Novak's car could still make a reasonable claim for injury compensation against Novak or his insurance policy. And if such an incident occurred involving someone who knew he was prone to blacking out or otherwise losing situational awareness, but neglected to obtain treatment, than that would constitute recklessness.
