When I loot goodie huts that are in forests, the tile remains a 'forest' tile if I put the cursor over it but the tile looks like a plain, and as far as I can tell, this doesn't refresh to the correct display either. Except for the appearance, it will still behave like a forest tile, too, impeding movement.

Also, at one point I tried moving one of my units to a square and was unable to do so. A turn later, up popped on the display an AI outpost where I had tried to move. That explains why I couldn't move there, but it's odd that it took a turn (at least) for me to actually see it.