You don’t think he could have found him again? It is not a particularly complex maze that they were living in.
Looking at the map it seems to me that Martin could have easily walked home at the point when Zimmerman loses him. It also seems to me that if Zimmerman found Martin after he had lost him the first time he would have told the dispatcher “I found him!”. It also seems to me that if Martin felt threatened at any time he could’ve called the police. It also seems to me that if Zimmerman intended to confront Martin he would have just pulled up alongside him in his truck instead of pulling his truck over and calling police.