Are some of these (fly), programs dependent upon cell phone reception? he would not have cell reception in that area.
All the popular apps (iFly, Garmin Pilot, Foreflight, WingX, etc.) work offline. The only time you need to be online is when you download the maps, airport- and terrain databases. I tried multiple apps over time, all of them would download the terrain database automatically with the intial setup of the program. Also, the downloaded data remains functional, even if it is obsolete.
In iFly, and I assume that this is similar in most apps, all you need to do is to mark the option to show 'Terrain Highlight' and it will mark potentially dangerous terrain yellow or red, depending on whether you are still slightly above the terrain or not.
In order to see my position on the sectional, as well as the 'Terrain Highlights', all I need to do is to launch the app and to wait up to a minute until the GPS has a fix. That's it.
If this gentlemen has however never activated the terrain warnings, uses an app in which this works differently, never downloaded the database or somehow messed up the settings, this is of course an entirely different story...
The map settings in iFly, on my (rather tiny) iPhone screen:
This is what the terrain highlights (the yellow and red markings) would have looked like at the crash site on the world area chart and at a altitude of 7,172 ft. Please also note the profile view on the top right corner of the screen. It shows you way in advance whether you will hit something:
Same position, bigger range. It appears as whether he could have simply turned around and followed the long lake to the southeast:
I think that such smartphone / tablet apps are a great and cheap tool for situational awareness in case things go sideways...