Cave-divers are expected (and taught) to carry reserve gas supplies with them. From the description, they had reserve supplies - enough reserves to search for an hour - but failed to recover their guideline within that time.
The issue was that they lost their guide-line leading to the exit, rather than running out of gas. In such a scenario, no amount of reserve caches could really solve that problem.
The issue was that they lost their guide-line leading to the exit, rather than running out of gas. In such a scenario, no amount of reserve caches could really solve that problem.