Warrant. They won't come looking for him, but if he ever gets pulled over again, a simple traffic stop may turn into a ride in the back of a cop car.
This is what they want you to think. Its wrong though.
But you did not sign a ticket promising to appear in court, which is the exact reason we are made to sign tickets. This kind of ticket goes to the car and by default its owner, not a particular driver.
In fact you do not have to even be a licensed driver to get one of these tickets. All you have to do is own a car that gets caught.