When Duncan rescues the child from the burning building he says, "I'll try to get us out of here." He ignores a window in the child's bedroom. He could easily have jumped outside rather than dramatically run through the burning house, except for two things. The first is that we didn't actually see what story the child's bedroom was on, and the second that, being mortal, the child would likely have been severely injured even by jumping through a glass window on the first floor.