@Miller,
Oh please, if he had a subdural hematoma it would have been evident by now.
Zimmerman has remained asymptomatic, and he
never received, or sought, any further treatment for the very minor injuries he received that night.
The photos of his head show no evidence of any repeated "pounding"--no bruises, swellings, goose-eggs, etc.
The physician's asst. in his own doctor's office, who he saw right after the shooting (so he could get medical clearance to return to work) testified at trial that his injuries were "minor".