I don't believe Zimmerman followed Martin after the 911 dispatcher said, "we don't need you to do that." Zimmerman parked his car at the crosswalk at the bend in Twin Trees Rd. We can hear him running in the 911 tape. The wind picks up as he does so and the 911 dispatcher said this was one of his reasons for suspecting Zimmerman was following Martin. This only lasts for 15-20 seconds. After Zimmerman is told he doesn't need to follow, that noise disappears after a few seconds and is no longer heard on the tape.
Judging by 15-20 seconds of running/hustling, this puts Zimmerman at the t-intersection. This is logical because it offers a view down the backyards and Zimmerman still wants to inform the police where Martin is. It is also where Zimmerman claims he was. From that moment, 4 minutes pass before the other 911 calls are made, from John Good, Jenna Lauer, etc. Zimmerman claims to use this time by going East to look for an address to give the police officers that would give them a better location, then turn around and head back to his truck. (He also probably looked down Retreat View Circle to see if Martin ever appears down the block). At the end of this 4 minute period, Martin and Zimmerman are fighting 30 feet South of the T-intersection. So the fight probably happened 3.5 minutes after the 911 dispatcher's message. In 3.5 minutes, Zimmerman moved South by 10 yards. This includes any steps toward Martin he would have taken when Martin called out to Zimmerman (this is in both Zimmerman's and Jeantel's stories). This also includes any grappling or retreating made by the fighting parties. So including the movement in the fight, Zimmerman moved at (30 ft/3.5 min) 0.043 miles per hour towards Martin's house.
Martin told Jeantel that he had lost Zimmerman, and Zimmerman told the 911 operator he lost Martin when he was at the t-intersection. So it doesn't seem Martin was hiding in the bushes the whole time at the t-intersection. Either Martin turned back toward Zimmerman, Martin somehow made a wrong turn when he was only a half city-block from his house, or this was the slowest pursuit in the history of pursuits.