Wow, a pretty harsh assessment there.

The low visibility situation like this one is where the GPS really shines. Taking key waypoints along the route allows you to navigate back down in zero visibility. There's no need to run the unit continuously to record a track or follow it back. If you are proficient at plotting UTM coordinates on your map then targeting those spots in the GPS allows you to navigate efficiently on new terrain, again in zero visibility. In this way you could safely take a different route down.

All the standard caveats apply (terrain association & map/compass first, know how to use it, don't rely 100% on batteries, etc etc).