Sounds like in this case they were injured in the crash and then night fell so rescue gear / an ELT wouldn't necessarily have helped all that much. There is a significant subgroup of trauma survivors who, although initially and superficially they don't look too bad, will die within a very few hours if they do not get sophisticated emergency treatment within an hour or so.
This PLB with integral GPS, which pinpoints you to 30m in 3 minutes, is my personal insurance:
http://furuno.inforce.dk/sw2575.asp
Assuming it works, all you need then is someone to come pick you up.
QDM