From what I can see, the deer is on the other side of the ridge line, so it might have come up the other side. If hungry enough, and tame enough, I think its certainly possible. I had a goat years back that would jump 4 feet up onto a chicken coop, then up another 3 feet up and across a 4 foot gap to the woodshed roof, then walk the length of the garage roof, 10/12 pitch, and jump down 8 feet from the eves to get around the fence. Deer = Goat. They are remarkably agile.