If you are reasonably co-ordinated and are not an amputee, drive with both feet. Then you have 100% control 100% of the time. But out on the open road left foot, braking is not as critical as when manoeuvring in a carpark. Most of the 'runaway acceleration' claims against Toyota are by drivers who stomped on the accelerator with their right foot instead of the brake, and Toyota has proved this. If the drivers had left foot braked, the cars could not have 'unintentionally accelerated'.