Never heard that one before. Seems like ABC News would have tried to twist that.
What he said was "He's got his hand in his waistband. And he's a black male." This was when Martin came back toward him, and he was able to confirm that Martin was black; he had only surmised it before, saying, "He looks black."
And it's quite a stretch to say that Zimmerman said Martin was "possibly armed," based on the statement that he had his hand in his waistband.