he might have not known who Zimmerman was. He might be thought someone was going to rob him or attack him. Some weird guy chasing you down could be a little freaky. Zimmerman might have had his gun out. Who knows?
Two people do not have to be up close to exchange information. Zimmerman just wanted to know why Martin was in the apartment complex. Simple question with a simple answer.
Mr.Zimmerman has, as a member of community watch, a history of informing the Sanford police of questionable or suspicious activity in that gated community. He does not, as far as I can ascertain, have a history of violent confrontations, something community watch folks are warned against doing.
If you go to the City of Sanfords online site, the telephone calls are all there as well as a report from the City Manager, Norton Bonaparte
http://www.sanfordfl.gov/index.html
http://www.sanfordfl.gov/investigation/docs/Zimmerman_Martin_shooting.pdf