That's Not Right

This guy goes out to his car and he accidentally trips the car alarm. Then, he gets in the car but he can't seem to turn the alarm off. So he starts the car and drives off with the car alarm blaring away. Everyone turns to look; and we're all wondering the same thing, "Did that guy just steal a car and none of us said a word?" But he's driving away like there's nothing wrong. He pulls up to the corner and waits with all the other drivers for the light to turn green - all the while that car alarm keeps going and going and going. It must be deafening inside the car, but this guy is driving away as if nothing is wrong. Maybe this happens to him all the time, but it does make a body wonder. If your car alarm is supposed to stop a person from stealing your car, why doesn't it prevent the engine from starting until after the alarm has been cleared? Just wondering aloud.