More than once over the past few years I have had "tag-a-longs" following our group down off a mountain trying to safely get back below tree line.

It happened once last spring in NH, Mt Adams if I recall, but, I'm not positive, we did that whole ridgeline. The people were so happy to see us coming down from a summit one afternoon, I thought they were going to hug us. They were disoriented, clueless, out for a "fun day in the mountains". When the clouds rolled in we were above them, and visibility really dropped. You could barely make out the next cairn on the trail if you were really looking. I don't think they even really understood how trails worked above treeline. Anyway, they didn't care where we were going, they just wanted to get below the clouds so they could see again.

I probably don't need to mention that they were underequipped, both in terms of actual "equipment", and in terms of training/experience...here's an example:
We had a couple instances where we had a guy head out to the next cairn on length of paracord, just because the visbility was so bad... well, our "tag-a-long" couple were horrified, because they somehow envisioned my buddy rappelling down the mountain on the 550 cord! (We got a pretty big laugh out of that one, could have really spooked them if we weren't so nice...)

Eventually we got them to an AMC hut (Madison Springs hut between Mt Adams and Mt Madision), and they went in for some cocoa and a sanity break. We kept going on our traverse, and for all I know, they stayed the night at the hut. Afterwards, we looked at it as having saved some poor SAR team from having to go find them later that night when they didn't come home.