A friend of mine was let off of what was certain to be a drunk driving offense because both officers who arrived on scene "forgot" the breathalyzer unit and wer

A friend of mine was let off of what was certain to be a drunk driving offense because both officers who arrived on scene "forgot" the breathalyzer unit and were too embarrassed to go back to the precinct and pick it up essentially. So based on that anecdoctal evidence, I would guess that they are mostly extremely out of calibration. (If they're just these weird machines that nobody keeps track of or knows where they are at all times)