I don't know. I didn't see any proof that it was doctored (wouldnt't surprise me if it was though), the logo covering Zimmerman's head may be a little suspicious though, then again I still have no idea what happened that night now that the two stories of what took place have been divided among political lines.
I was wondering if the caption was accidently or intentionally placed. I don't think ABC could have done a better job if they tried placing the caption if it was an accident.