If you look at the second to the last photo on the webpage, you can see at least one white stripe running diagonally through the Balkankreuz across the front of the hull.
My guess is that this is the remains of a rather sparse winter camouflage and the crew of this Wehrmacht employed T-34 mistakenly drove the vehicle across the snow covered, frozen bog, thinking it was just a meadow, and fell through the ice. I'm sure this happened countless times throughout the war, that is why we keep seeing folks dragging these beasts out of swamps. No one in there right mind would have driven a tank straight into a swamp if they could see it.
Peat bogs are remarkable for their ability to preserve things which has been dropped into them. The low oxygen levels, cold temperatures and reducing environment of peat bogs have lead to some spectacular finds of animal and human remains being recovered after centuries and even millennia of burial. The Iron Age Bog Man of the British Museum in London is a prime example. Skin, hair, fingernails, cloth, leather, even tattoos have been preserved. If the crew of this tank did not make it out alive, chances are they would still be preserved, albeit a lot worse for wear and tear, inside the vehicle. Notice the almost total lack of rust on this vehicle, an indication of the low oxygen, reducing environment that this tank has sat in for the last 60 odd years.