One part you may include is that after a certain time going in the wrong direction people start believing they are on the right track again. This is only administered when the person discovers it and alters course. So something simple as just taking a wrong bearing, one of the two forgot rainproof weather gear =slight hyperthermia-denial.

remember a survival situation doesn't happen because of 1 big thing but mostly because of smaller things happening in a row. That and taking wrong decisions