My $.02 on this deal.
toyota was neglagent.
here is why I think that.
Murphy is a SOB. Knowing that, one logically, would program the throttle control software to where when murphy strikes, the engine would not got to WOT. GM, For example has a max of 40% throttle when the drive by wire system is throwing out errors. Ford, MB, honda, BMW and several others have simlar systems. Toyota does not. why is it every one else was smart enough to figure it out, but toyota was not? That is the big question. I'd bet money is envoled in that answer.
It does not matter if some vendors part is bad or not, your software still has a HUGE oversite in it.
Now I can't speak for japan, but here in the states, every single engineering class, at some point teachs murphys law.