You’re absolutely right, it’s still 100% the responsibility of the driver, FSD or not. I’m no fan of FSD, in part because of situations like this.

But your hatred of cars is clouding your judgment here. Calling all cars “weapons” has some merit where cars and pedestrians/cyclists have to co-exist, but on freeways such as this where pedestrians are legally prohibited it falls a little hollow. That someone was crossing 12+ lanes of protected freeway (meaning is separated by fences or walls) at 2:35am is very very unexpected, making it more of an outlier than indicative of anything. It also points to mental health or some other impairment of this 71 year old person, which like you said could’ve been a deer or something.

Like it or not (I’m guessing you do not, and I don’t blame you) this happened in a car-centric area; I only bring that up because I think it’s reasonable to not expect pedestrians where they are legally prohibited. Of course, that does NOT resolve the driver of any responsibly, but it does explain it a bit.