Unintended acceleration and brakes not stopping the car are two completely different things...

Often times people push brake and accelerator pedals at the same time. This is attributable to large shoes (talking about width as well as length). You can tell this is happening when you push the brake and see the jump in the RPM. Happened to me this weekend with my snow boots on

Another note about RWD vs FWD brake system: front brakes do most of the braking in either drive system...