Since the accelerator is drive by wire, pushing both pedals disables the accelerator, and produces a warning chime and alert message on the screen.
The brakes do not have to be stronger, it’s handled in software.
If the accelerator is pinned down, letting up on the brake will cause the car to start accelerating again. So you have to keep on the brake and then put the car in park. Pressing the accelerator while in park does nothing.