After finding the Mexican army gone the next morning, Taylor held a council of war in which seven of ten officers voted to wait for reinforcements, Taylor brushed their objections aside and ordered the army to advance. According to one account, Duncan was one of the three officers voting to advance. In another account, Taylor encountered Duncan who remarked, "General, we whipped them yesterday and we can whip them again". Unknown to the Americans, the Mexican soldiers were demoralized by their heavy casualties. In the Battle of Resaca de la Palma on May 9, the Americans routed the Mexican army. The Americans sustained losses of 34 killed and 113 wounded, but Mexican casualties were much heavier and included seven artillery pieces. Duncan was breveted major for "gallant conduct" at Palo Alto and breveted lieutenant colonel for "gallant and highly distinguished conduct" at Resaca de la Palma.