That's a spooker.

I live where there's lots of whitetails. It's hard to overstate how dangerous it is to drive around here, even worse to ride a motorcycle. Everyone has a story about a deer hit or two. Many times I've heard the story of how the deer "came out of nowhere and slammed into the side of my car!" I've seen deer cross the road in front of me at a 90 degree angle that had to be going 45 mph or more.

I think that if a deer is spooked and running at full speed it only focuses on what's directly in front of it and doesn't expect to be hit from the side. Sucks to get hit by a deer running full speed from the side, 'specially on a bicycle, ouch.