There is no other way out. If there is an injury that requires outside medical attention then the trek will have to be aborted for everyone. No one on any of the 20 backpack trips to New Mexico, Colorodo and Mexico nor anyone on the 15 canoe trips in the Big Bend National Park that I have planned and led, has ever had a serious injury. We have been very fortunate but we have also, by and large, had teenagers that were adult in their attitudes. Horseplay and daredevil acts simply are not acceptable 20 miles from the nearest car.
Some adults are often more prone to injury than teenagers because of attitude.
Even if you didn't pack it in - leave it better for the next guy. Anything that doesn't burn must be carried out - not buried. Aluminum lasts forever and foil in campfires is the most common sin of backpackers. Try to always get water from springs and avoid the large streams. Above 10,000 feet elevation we will drink water straight from small streams coming off mountains with no trail crossings.