When I played through the Demo (in DX 10/11 version), a two sides of mountains near to my start area were that same red throughout the entire playthrough (no other mountains affected, and a 2nd Demo playthrough didn't see any of it).
I ran into a bunch of graphical glitches like this last night in my game
There were those weird red dots all over the map. There was also incorrect textures, like in the ocean there was a random tile of land. It wasn't connected to the nearby continent properly and hovering over it listed it as ocean still.
Also the game would show units that weren't actually there. I was at war with Germany and they showed an archer unit which embarked and was sitting in the middle of a bay that I had 2 caravels and a frigate sitting in. I thought that was odd that they would do that, but figured I'd kill the unit quickly anyway. When I moved close to fire the unit instantly dissappeared and the archer unit was back on land where it was before it showed them as entering the ocean.