Weather Conditions in a replay?

[Plain Ian]

I've just watched the turn replay from my veteran opponent Indragnir. He's playing the Germans in Bulge and giving me a master class on defensive tactics and showing me how the Germans should have won the war. 

He is first player in the Turn, and during the replay the terrain visible was clearly MUD. However some of the moves looked like they were non MUD moves eg moving in woods AND still having MP's to fire.

Can ground conditions change in between player phases? Or was his turn/phase a non MUD phase but the game still shows the MUD terrain?