Hi Bruce -you seem to be forgetting the Exposure Compensation (EC) part of spot metering. If you meter the shaded area, or any other area for that matter, it is YOU who decides how you want that area exposed. See the Kodak chart that I posted earlier and look at the 'EC' column.
So, -take the shaded log wall in your shot- you would spot meter it with zero EC.
It might tell you f/8 at 1/100 sec. As you should know, if you leave the EC at zero, the wall will come out mid-gray.
However, lets say that you want it to come out light gray, you would add 2/3EV compensation (so now f/8 at 1/60 sec) but then there would be a chance that the clouds at upper left will blow - but that is your choice. On the other hand, if you wanted to retain some cloud detail, you would spot-meter the cloud and add say 2EV compensation to make it not gray. In that case, your log wall could come out darker than you would like -but you can't have it both ways.
Exposure Compensation - a powerful tool when spot metering, or any other kind of metering for that matter.
HTH.