If you drove a Prius (I do) then you would know A) Prius's don't usually have a key in the ignition and B) you can't turn the car off while accelerating.
Do you understand this is a software issue, chief? You have no clue what is going on. For all you know, the entire car might be unresponsive. Ever had a computer hang on you?
Though make sure you can go straight for awhile, as it will also disable power steering.
What difference does it make if a problem is "hardware" of "software" (or even user error for that matter), if it's common enough and if it results in loss of life?
I was not arguing that Toyota shouldn't fix the problem, only that bugs are routine and we shouldn't pretend that there is negligence here.