I don't want to second guess the couple too much. Their decisions worked, and didn't get anyone else involved to sort out their mess.

But I agree with your assessment, terrain, weather, time of year and time of day would make my decision for me. If I was starting out after a full day of fishing or the weather had the potential of turning poor, I personally would probably wait until morning and then walk the road back on the road. The expectation being that if I don't make it out before rescuers are called, I can meet them on their way in. This option also helps make up for lack of detailed maps of the area. I'm used to walking with either 1:24,000 USGS, or 1:25,000 military topographic maps. Detailed enough to plot your position within a 10 meter square with a lensatic compass. If I just had a road atlas, I'd follow the road.

If I was starting out early in the day and the terrain and weather looked fine, I would probably follow the same course of action they did.

Its not a situation that really required rescue. It could have turned into one but so can showering. They did their duty to any rescuers though, by leaving a plan before they left home and before they left their car.