That said, examining this critically: how would someone from the other side of the border observe people going up the mountain, going inside caves, and falling to the ground and dying in droves? Did he go inside the caves himself and found the corpses, and if so, why? If he didn't, how did he know how many died? Did he count people going in and going out the caves? Did he conduct a census of North Korean villages beyond the border and saw a stark decline in population, and was the only possible explanation starvation in caves (vs, say, migration)? If this is something that's common knowledge in the driver's community, the question becomes how did this community come to "know" all of this.