Where was that the general image? Zimmerman had his own words edited, misinterpreted as racial slurs, and his injuries seen as non-existent. Martin was just a kid walking back from the store killed by a vigilante that didn't want some black burglar to escape. Plenty of people considered the possibility of Martin defending himself against a creepy racist stalker, but there's not much to support that outside of the testimony of his friend on the phone's claim. It's possible that Zimmerman tried to restrain Martin which resulted in Martin attacking Zimmerman, but what? Did Martin gain the upper-hand and continue to attack Zimmerman for 45 seconds, past the point of what would be considered self-defense (and FWIW if that was the case I would find myself much more on Martin's side)? Was it really Martin screaming for help after all that time while Zimmerman held him down for a prolonged period without leaving any physical marks? They are possibilities, but remote ones. The case for Martin acting in self-defense was simply weak, so if the media on a whole really didn't consider it (certainly you had your Nancy Graces that did) it was because there was little reason to consider it.
