I haven't been on that trail for a few years, so perhaps it has changed. I suppose around stream crossings, it might take a little orienting to pick up where to go and perhaps they took a game trail that led the wrong way. The other thing that is strange is that this is a pretty well traveled trail. I don't think I have ever been on it and not seen several other parties.
I don't doubt their story, I'm just mystified. I wonder if substance consumption or mental limitations might have played a part.