I think everyone saw this 'phenomenon' in DR2, presenting wet surface to be looked like covered by snow. This one I spotted on recent video posted by @PJTierney. Here is a screenshot from this video modified in order to explain the issue. What I've done (besides desaturation) is I stretched pixels found inside a puddle upward to compare their brightness with a sky. (click for original size) As you can see, reflection if water is way brighter than image being reflected (sky).