I can see it being easy to run over the deer, if the snow was deep and they got spooked into going off the packed down trails.
You could catch them walking on snowshoes in deep snow.
I have personally rode right up by them in northern Michigan in deep snow.
In the deep snow, once they get spooked off the packed trails or their yarding area, they are doomed to anything that wanted to catch them if it can stay on top of the snow.
Anyone that has ever tried to walk in 3 feet of snow would understand how easy it could be to run over those deer.
I had never thought of deep snow. That definitely brings up another scenario. I live southern Indiana and deep snow if very uncommon. We had 2 feet of snow but that was 4 or 5 years ago.