Chances are this deer was no sick or infected with CWD. Chances are this deer had severe internal injuries from eith being hit by a vehicle or some other reason. If a vehicle hits a deer it doesnt always leave any noticible marks, I have hit 23 deer in the last 15 years and most of which all got up and walked away like they were unharmed. This deer could have been hit moments before you arrived to it. Im going to say this deer was dyeing of internal injuries.