As I can see from the image and the exif, all I can say is that the fog and dimmed light have made your image underexposure. Ofcourse it's not seen by human eye for their remarkable auto diaphragm and speed are almost unlimited.
Maybe you can try put slower speed (since there weren't any movement) and put apperture priority to 5,6 or 8.0 then let the shutter adjust it's self. It'll darker but it shouldn't lost focus.
Another way is bracketing take few shots with different SPEEDS not the Apperture.
Hope it'll works.
