And what if they got lost while trying to find their way back?Then they would have a serious problem. They should STOP!

And about the candy part: They didn't survive for three days bacause they ate that candy.
Candy is just a moral booster so it doesn't fight of hunger very long. In a 3-day situation you don't need food, only water and they had that.

Why they survived? Just very lucky to be found I guess....... Had they survived much longer without help: I don't think so......