If you are attempting to self rescue yourself then heading downhill and following water will lead to civilization - sometime in the future.
If you ain't got a clue - and looking at the pictures they don't - then staying put prevents you from wandering farther from the possible search area - or into an area that had just been searched the day before.
Interesting that between the three of them they didn't have anything to build a fire with.
Yikes, possibly a very good thing they couldn’t start a fire!
I remember a couple years ago in San Diego - a drunk guy out ‘hunting’ with a few buddies got hideously drunk - lost for a couple hours - and rather than flowing downhill (something in San Diego county that will lead to other people in less than a single days) - he decided (in Santa Ana conditions) to start a “Signal fire” that soon got out of his rather limited control - and went on to be one of the most destructive fires EVER.
The guy was something like 30 years old IIRC, of hispanic nationality, still living at home. His picture is in the Dictionary under “stupid loser” and “what not to do when ‘lost’ for a few hours in San Diego county”.
What a maroon!
My guess is that they had already smoked it.
They didn’t have anything to build a fire or even a lean-to shelter. No compass ,no map section of the area,no even basic knowledge that you can get from Outdoor Life or Sports Afield these folks are a Darwin Award looking for a place to happen.
So they were going to eat their pet dog raw and uncooked.