"Survival camera" is an oymoron - hardly anywhere near being a critical element. On the other hand, I du use my cell phone camera daily to document work involved situations and it is perfectly adequate for that purpose. Since the cell phone has more direct survival loses (witness the recent SAR in Trabuco Canyon) you do indeed have a camera with you so you could photo your surroundings, extent of injuries, etc as an aid to rescuers. But a camera is in no way a critical item.