Auron followed the bandit group, who were escaping in fear. Because all of them were in fear, they didn't have time to pay attention to Auron.
Auron occasionally threw one or two spells to scare these bandits off. He didn't have any intentions to chase them all the way and killed them all. It was because a cornered beast could become dangerous. Moreover, he was alone right now.
Auron chased them quite far from the village. When he felt it was enough, he looked in the bandit's leader and the young man's direction. Then, he estimated the direction they went and compared it with the base's locations that he had. From there, Auron got three base locations that got the most significant possibility for the leader and young man to visit.