Had Trey noticed that the drake was fleeing, he probably would have chased him down and finished him off. Since the human posed more of a threat, though, Trey was focused on him. The human was fast enough to outrun everyone in the group, firing the occasional arrow at them as he ran. Those who were more melee-oriented had to resort to throwing their weapons at him. Trey kept pursuing the archer, and shot another Fire spell at him, hoping to actually hit this time. Unfortunately, it ended up missing again. Perhaps it was the human's agility that was throwing him off.