I don't see this as an ethics question. I see it as a wilderness medicine question.
The issue is, what steps should you take to best care for this patient. I don't have my little cheat sheet with me, but to my recollection, if you have a WFA class in your background, then you'll probably stabilize the spine, check airway/breathing/circulation, check for vitals and conduct a full patient assessment. Based on that (e.g., is there bleeding or obvious trauma injury what is pulse, respiration? Check the CSMs. Is the person still unconscious? Is there an apparent mechanism of injury? Do you know anything else about the patient history -- use of meds perhaps-- that could be relevant), you'll decide the next course of action. If you conclude this is an evacuation emergency and the patient cannot adequately be cared for by you, you probably will do what you can to get the patient warm and protected in your absence (inside a tent? In sleeping bag? Water/food available if he/she comes to? ) and go for help. For a suspected head injury, spine should be stabilized, head elevated 6" above body, airway kept clear if possible.
The NOLS WFA class teaches protocols for backcountry event like this. Well worth taking.
WFA-wilderness first aid. Available everywhere including an REI store near you. Expect to pay about $200.
