If you step on the brake it will overcome the accelerator every time no matter how hard you rev the engine.
I have a counterexample:
5-6 years ago, I was driving my wife's 1997 Ford Taurus when the accelerator pedal stuck to the floor. I pressed the break as hard as I could (both feet and as much of my 220 pound weight that I could put on it from a seated position), but we continued to accelerate. Thankfully, I was able to put the car in neutral before we crashed into anything. I coasted to the center turn lane, put on the e-brake, and sat there calming down, with the engine redlining until I shut it off.
I know with 100% certainty that I wasn't pressing the wrong pedal - the accelerator was still stuck to the floor after I got help from a cop to push the car into a parking lot. This was a mechanical issue (not many manufacturers were doing drive-by-wire throttle back in 1997); the engine had just been rebuilt, and the shop must have reinstalled the cable incorrectly - among other things they screwed up.
This car was fairly old (probably 130k miles at that point), but the brakes were well-maintained, and they were four-wheel disc.
You might be right for some - perhaps most - instances, but not 100%, as my experience proves.