I'm more and more inclined to not rely on any one form of navigation.  Map and compass is great, but using a GPS occasionally to confirm gives confidence to the compass/map.  In this situation, a GPS would have shown them going astray. . . 
SPOT and PLB's are good for emergency situations like the one described.  Not getting lost is great. 
_________________________
Better is the Enemy of Good Enough.  
Okay, what’s your point??