@parados,
Some people don't know the difference between something verbalized at trial doesn't equate to evidence.
There were no witnesses who saw Martin bang Zimmerman's head against the sidewalk cement.
That the prosecution failed to challenge OMara's show on how "it could have happened" is the failure of the prosecution attorneys.
If in reality, Martin banged Zimmerman's head against the sidewalk as OMara had shown it, Zimmerman would have had worse injuries, and he would not have had the strength or ability to grab his gun and shoot Martin. All the evidence presented during trial showed his injuries were minor (and not traumatic). Those are the FACTS from the trial.
Zimmerman refused to be taken to the hospital for further treatment.
Those who keep bringing up this issue have more imagination than OMara.