The third test simulated a racing engine causing the car to speed out of control and the driver reacting by just hitting the brake pedal as hard as possible. Even though in this case the brakes had to overcome the motive force of the engine, they did. The car came to a halt in 148.8 feet, a distance that perhaps a large, heavy-duty pickup might make under normal maximum braking. With practice (this is, after all, a non-standard test), Josh was able to whittle this distance down to 129 feet. In other words, even if the driver of a runaway car (well, a Camry, anyway) doesn't think to put the transmission into neutral before hitting the brakes, it is still possible to stop the car within a reasonable distance if sufficient pedal force is applied.
The take-away from this is that it is possible to stop a runaway car (or at least a Camry) even if the racing engine is left powering the drive wheels. But to do so takes maximum-effort braking. As this isn't something people practice, they may think they're hitting the brakes hard enough when they're not. To overcome the engine's force, you must stand on the brakes for all you're worth. It's actually worse to just continuously use the brakes moderately hard, as this will not cause the car to stop; instead, the brakes will quickly overheat and fade, becoming ineffective. Think of somebody riding their brakes as they descend a long, steep hill — the telltale smell of burning brakes (and the subsequent fading of their ability) is unmistakable.
Although it is possible to stop a runaway car with a racing engine working against the brakes, we cannot emphasize this enough: Should you find yourself in a runaway car, immediately put the transmission into Neutral and then brake as you normally would to bring the car to a stop as quickly and safely as possible.