IANAL, but: It circles back to the right to fair representation.
Say he’s convicted, but at a later court, claims “After my totally involuntary psychotic episode, now verified by multiple behavioral psychologists, my lawyer held my unintentional actions against me and did a demonstrably poor job in the remainder of the case. I deserve the right to a fair trial.”
That COULD be enough to get the case declared a mistrial and re-scheduled.
When I boil down the very moment of his decision, I agree in the idea of self defense. But it’s also why I’m generally opposed to filling an environment with high-lethality machines (be they guns, OR cars). It’s naive to put confidence behind the minds in control of those objects. Highways, too, have a high rate of deaths; but they at least serve some useful purpose.