My take is if he is smart enough to survive for for 17 days, he should have been found sooner. It is hard to believe a 70 year old man that spent the day fishing from a kayak decided fishing sucked and decided to hike a mile or so to better fishing grounds and got lost. It just doesn’t add up...
The wind kicked up making kayaking difficult. He could have stayed and fished from shore. It sounds like he was heading out, saw the road to the lakes and thought that might be fun in the time he had left in the day.