noise on the 5d ii
Might want to meter off the sky and bump it +.7 or +1 during the capture when you have a dark middle ground and foreground. -1 EV for this scene is not the ultimate choice.
There is nothing wrong with your camera, and there is nothing wrong with a little underexposure as long as you don't go overboard and know how to fix it in post if you do. I'm not saying you made any mistakes, just making some generic statements about exposure.
Although this would print fairly dark as is, I'll venture a guess that the pixelated sky would clean up in print. The view on screen is a little misleading.