A US Army mechanic who refused to go to Iraq while he sought conscientious objector status was acquitted yesterday of desertion but found guilty of a lesser charge during his court-martial. Sgt. Kevin Benderman was sentenced to 15 months in prison on the charge of missing movement. He also was given a dishonorable discharge from the military and a reduction in rank to private. If he had been found guilty of desertion, he could have faced five years in prison. Still, his sentence appears to be the harshest yet given to an Iraq war resister.