I agree with what you are saying in regards to those aspects. It is mainly the walls and the certain other areas that look really flat to me. Could just be due to the large open world. Not a big deal, just something that stood out to me, probably more so since the rest looks really good in contrast.
edit: That is a good way of putting it Big Brad.
Just found an example (clicking on picture brings up the large version which shows what I'm talking about better):