A properly trained concealed carry carrier would have never let Trayvon get that close to him, let alone sneak up on him from behind. But then, hindsight is always 20/20 and I’m sure Z has kicked himself for his mistakes that night.
This is where the education meets reality. I have no idea how the contact was initiated, but I have a feeling the Trayvon was a bit more spry than Zimmerman and could close distance on Zimmerman from behind or the front more quickly than Z could compensate.