I may be wrong, but he looks like a very fit and able man who has probably spent much of his life pursuing sports. I have a few GP friends and they all cycle long distance, take adventurous holidays and general don't like to be idle. I can well imagine someone like that not thinking twice of taking a mountain track, especially if someone tells them it's a matter of an hour. Tempting for someone who feels physically fit.
He's clearly a very intelligent individual, I'm sure he risk assessed, perhaps seeing the traffic as a higher risk that the mountain track. Or perhaps thought that was boring and wanted an adventurous walk back home.
Sadly, I suspect he won't be found alive. I can't imagine (although may of course be wrong) that he had much food or water with him, certainly not enough to stay alive over 3 days. I think it's highly likely this is now a recovery operation.
I really feel for his family, the unknown must be torturous and all the what ifs. My thoughts are with them all and every other family who are waiting for a loved one to return or be found.