Did you see the video? It's a security camera. You can hardly tell who the guy is, let alone make a medical analysis.
Edit: Here it is. Right around 1:06, 1:07, you can see a cut on the back of his head. This is after he was checked out on the scene. He was cleaned up already, so there isn't blood all over the place or anything like that. The video is too low quality to see if his nose is purple or crooked.
http://abcnews.go.com/US/video/george-zimmerman-police-surveillance-16024475
Edit: Here it is. Right around 1:06, 1:07, you can see a cut on the back of his head. This is after he was checked out on the scene. He was cleaned up already, so there isn't blood all over the place or anything like that. The video is too low quality to see if his nose is purple or crooked.
http://abcnews.go.com/US/video/george-zimmerman-police-surveillance-16024475