I think people are getting confused. In order to give the police the best idea of where the perp goes, one must observe that. If that means get out of your truck to do so, your in your legal right. Pursuing and Observing are 2 different things, It's his job to observe and report. That's what he was doing, if the kids still in the neighborhood, he can observe him from a god damn drone if he wants. The issue isn't Zimmerman observing and then losing sight and (from his testimony) retreating back to his truck. The issue is trayvon PHYSICALLY assualting Zimmerman. That's when the self defense situation begins. At physical contact. Period. (if that's indeed what happend) we will never know though.