You are correct. A penalty is the result of being caught for committing an infraction of the rules, I.E. cheating. :)
And this is where you and the whole gist of the thread is fundamentally wrong. "Cheating" implies malice aforethought. It implies breaking the rules intentionally in the hope of getting away with it.
An infraction can be the result of being fooled, out of position, or simply being too anxious to get off the ball when the QB does a hard count.
I can't believe I have to explain this.