HOLY CRAP is putting it mildly. Thank the GOOD LORD that you survived and you are able to tell us about it. I wish you all the physical and mental strength you need to put this incident behind you.
I have been watching the Toyota situation for some time and I'll put my money on it ultimately being a problem with either the electrical wiring or the computer program or both causing the sudden acceleration.
That being said, I'm far from a confidence level with the "Throttle By Wire" on my '09 SEUC. I have experienced sticking throttle cables in the past both with carbs or FI, but since that happens AFTER you open the throttle, you are expecting the motor to accelerate and can deal with it via clutch / kill switch. Having a motor go from idle to full throttle totally without warning will put any of us on the ground. Not good!! Hmmm, I have had heated grips repaired twice, both due to "bad wires in handlebars", what's next?
Again, best wishes to you and keep us posted.
Tom P.