I've said it before and I'll say it again, a broken nose is not really a big deal. It may and usually is not even really noticeable unless you saw the person immediately before and then immediately after. I say that as a person who had his nose broken twice in fist fights. And in neither case did I get so called black eyes. And an abrasion on the back of the head that results in bleeding, unless there is a patch of dried blood won't show very well either, so this video is really not dispositive at all of that issue.
What do you expect a broken nose to look like? The break is, after all, just cartilage inside of soft tissue. And it may or may not result in bleeding.
Zimmerman's lawyer and Joe Oliver both said Zimmerman had cuts that required stitches on the back of his head, from Tayvon bashing Zimmerman's head on the ground. They said he didn't get stitches because he went to the police station. Video- no cuts.
You could not see a laceration of the scalp in hair in that video, nor would you necessarily be able to. What would you expect that to look like? If he had it cleaned at the place of the incident by the EMTs who looked after Miller, they would not have put a bandage on a scalp with hair on it, would they, unless it hat been stitched. Are you expecting a gauze wrap around the head? A laceration of the scalp however small is still a laceration and would not necessarily be visible in that video IMO. Bashing the back of a guys aead on the ground would not make a large open wound. I've done that a few times to subdue guys I had down, and afterwards they didn't attract a lot of attention to the other guys around them in the barracks where it had just happened.
It's all a matter of record. I have a notion all this discussion is mostly inuendo.