Exactly what I was thinking Bulldog, bet there is no one along that trail this time of year.
The Crabtree station and the summit hut are the only reasonably accessible shelters in that area, right? For a dayhiker in trouble without overnight winter equipment, those would be the primary targets for survival - to my thinking anyway. Presumably he would have been noticed at the summit hut. Just not a lot of other options if his car is still at the Portal lot.
I get a chill down my back whenever I look at the current webcam shot and think of someone in distress up on the mountain.