The general rule is that you throw out your best witnesses early and then use the lousy witnesses at the end. Sometimes you save your best witness for last, but since first impressions are the most important, you usually send in the best witness early.
So far the State has not proved any element of the crime. They still haven't established that George Zimmerman was the shooter. All they have is a dead body and a bunch of witnesses who either back up Zimmerman's story (which has not yet been presented) or who have significant credibility issues.
The best witness by far was the Neighborhood Watch lady. She obviously liked Zimmerman and Zimmerman obviously liked her. The Prosecution failed to get anything of value from her. They called her up to establish an evil motive by Zimmerman and it backfired big time. She made Zimmerman look like the most responsible person in that neighborhood.
I totally agree.