Oh no a bloody nose totally indicative of someone trying to kill him instead of punching him once.
That picture entirely supports the medical examiner's testimony. Unless you have evidence of more attacks as can be seen in that picture, then the medical examiner is currently the most reliable testimony, since the evidence actually supports it.
Sorry, nickerson, but I think you're stretching a little too hard to try to play Devil's Advocate.
Furthermore, I would like to point out one thing: There is one incident of Stand Your Ground that actually should've applied. A black woman was being attacked by a bunch of men. She shot her gun a few times as a warning shot. She didn't even kill anybody. She was convicted for 20 years. So if Zimmerman gets acquitted, then I'm giving up all hope for Florida.
Additionally: Unlike in Phoenix Wright, Eyewitness testimony is unreliable. In fact, it's the least reliable form of evidence that can be presented in court. It was dark. It's hard to see who is who in that situation. And, guess what? MEMORY IS FALLIBLE. Especially during intense situations. And it's also easily tainted by suggestion.