1. It was to function as a beacon when the group fled the tent. If it was turned on, though, the batteries would eventually die. Yet the flashlight worked when found by the search party.
2. When the tent was moved to the slope by the people staging the tragedy, someone inadvertently left it on top of the tent. But assuming the tent was moved and pitched in daylight, why was someone carrying a flashlight?
3. The group was attacked at night and one of the attackers placed the flashlight on top of the tent, but then forgot about it.
Other explanations? Maybe this one flashlight is an absolutely crucial clue?!