Is it possible for a minor being charge with a DUI to get the charges dropped?

My boyfriend got pulled over for throwing a cigarette out the window on midnight. Then, FOR NO REASON, the cop gave a sobriety test to him. The cop did NOT ask him if he had any medical conditions that would mess up the test. Then he blew a .09 at the car. When he was arrested, the cop said he was in full control of his vehicle, and he was also very respectful and cooperative. He did not get charged for littering. When he got to the station, 30 minutes later, he blew a .07. This makes me think that maybe the machines were calibrated wrong, and if thats the case, it is my understanding that the charges should be dropped entirely. He was in the State of Washington when this happened. Is it possible to get the charges dropped or lowered? He is 5 months away from being 21.