Self Accelerating When Fully Charged

A few weeks ago I was going down a large hill and shifted to dynamic braking. Long windy road and had dynamic breaking on for a while. Maybe 10-15 minutes. Some uphill. Most downhill. When I started hitting more uphill again I shifted back to drive. I then noticed that when I took my foot off the pedal my car didnt slow down (even when going uphill). It actually was accelerating one mph every few seconds. No foot on the pedal.

I tried using my foot to pull my accelerator up incase it was stuck but it seemed like it was in the released position.

I pulled over and turned on the hybrid system monitoring (the little dynamic diagram of where your gas motor and electric system are pushing/pulling power to/from and I noticed that my battery was full. Regen breaking still kicked on when accelerator was released even though the battery was topped off. My thought was maybe my battery is so saturated that my system is trying to continually dump power into the wheels even when the accelerator isnt depressed.

I doubt this would be an intentional design but it wasnt until after my battery stopped reporting full battery did my car stop behaving like this. It was self accelerating for maybe 10 minutes.

This happened again last week. Maybe for a minute. Again started after a period of dynamic breaking.

This never has happed under normal conditions (no dynamic breaking).

2012 Prius IV

 

I guess its a possibility? But i'd think low since i'd have to unknowingly set it and then unknowingly release it. I definitely was looking at my dash and didnt notice cc set.

Maybe I find a hill and test it out again..