Could very well be, but when every story I've read starts off with a racial slant that is errant in the facts leads me to defer judgment till more facts are available. He wasn't charged and has only become an issue due to the ongoing erroneous claim that this was a black child shot by a white man. Zimmerman is clearly hispanic by his statements and photo from a multicultural family. While he may very well be guilty of stupidity and possibly chargeable offenses, when a story is this factually errant and emotionally driven, justice will not be the outcome as evidenced by the knee jerk condemnations in just this detached thread on a gun board in TN.
As to the directions of the 911 operator, they are also notoriously documented as recommending against any individual response, preferring only police action to self defense. They are not legal advisors nor are they informed enough to make any judgment calls or recommendations.