Under stress, one's ability to reason degrades significantly (personal experience speaking0. This is just one more example, with a tragic ending.
Most often, you best get is to stop, make yourself conspicuous (bright clothing, signal mirror, etc) and save your energy.

he very likely was thirsty and may have been seeking water - a definite exception to the above guideline. Always carry a bit more than you think you will need.
Why didn't he just dial 911 direct and seek assistance? His phone could have been tracked, simplifying the rescue enormously.