Though the apology humanized the defendant, it also build an anticipation that Zimmerman will testify at his trial. If he does, he will be hit with any inconsistent statement he gave to the police -- and perhaps even to Sean Hannity. Yes, Sean may have become a State rebuttal witness.
More importantly, Zimmerman will have to explain not knowing there was no weapon since Martin was pleading for help. http://soundclick.com/share.cfm?id=11548279
Indeed, why would Martin plead for help if he was armed and could have fired his own gun? The “help” pleas went on for almost a minute, and thus unequivocally put Zimmerman on notice that Martin was at his mercy -- without a weapon to resort to.
It was disingenuous then for Zimmerman to say in open court that he did not know if Martin was armed. This undermined the sincerity of his apology.