DC and Jaskin - you are both right, a cell phone may not be close enough to a repeater to work. if he had been close to a road, though, he may have been able to use a walkie talkie. (I've always wondered what happens when you dial 911 on a cell phone). had he been in a canyon the mirror may only be able to be used during daylight hours, the flares may be obstructed by the boulders' position, etc.; but he may have been able to start a brush fire. not too many people carry road flares in their back packs.
anyhow, he broke two cardinal rules - never go alone, and always let someone know where you are at. not too much you can do if you are in the wilderness, though. someone may have found his car (where he could have left directions). and nothing like a gun going off to attract attention.
mountaineering accidents happen all the time. (just like drownings). some can't be helped. others can.
i just hope that I am never in a similar position.