Here is my theory.
GZ was on his way to the store when he encounters a suspicious guy:
"We’ve had some break-ins in my neighborhood and there’s a
real suspicious guy."
"This guy looks like he’s up to no good or he’s on drugs or something. It’s raining and he’s just walking around looking about."
"He’s here now … he’s just staring."
"Now he’s staring at me."
"Yeah, now he’s coming toward me. He’s got his hands in his waist band."
"Something’s wrong with him. Yep, he’s coming to check me out."
"He’s got something in his hands. I don’t know what his deal is."
The last two lines indicate to me that TM was trying to intimidate GZ. If TM was really scared of GZ he would have tried to avoid him. That was not the case.
Next, TM takes off running toward the back enterance.
I believe that because TM was trying to intimidate GZ, this lead GZ to further believe that TM was up to no good. This caused GZ to want to make sure that the police were able to talk to this individual, determine IF he was actually up to no good, and determine why he was trying to intimidate GZ.
GZ decided that with police on the way he wanted to be able to give the police a location of where TM went, or at least the direction of travel for them to follow up.
GZ got out of his truck and started to follow TM.
Dispacher: Are you following him? [2:24]
Zimmerman: Yeah. [2:25]
911 dispatcher: OK. We don’t need you to do that. [2:26]
Zimmerman: OK. [2:28]
At this point I dont believe GZ had sight of TM as evidenced by the following statement:
It’s a home. It’s 1950 – oh, crap, I don’t want to give it out – I don’t know where this kid is [inaudible] [3:40]
He was hesitant to give out his address, because he thought that TM may still be in earshot, and did not want retaliation for calling the police.
I believe that GZ then either stood at or near the T in the crosswalk waiting for the police to arrive. I believe he did this because he was hoping to get sight of TM again to further report to the police. My opinion was that TM was somewhere close by, probably watching to see what GZ was doing.
I think TM was pissed that GZ was watching him earlier (the clubhouse staredown), was still looking for him and decided to confront GZ. At this point TM started walking toward GZ and said something to GZ. To me "You got a problem" seems to make more sense than "Why are you following me", but I dont know that it matters. I don't believe that GZ ever intended to confront TM, but here was TM approaching GZ.
I think words were exchanged and TM struck GZ in the face breaking his nose. GZ fell to the ground and TM jumped on top of him and continued punching him in the face. GZ tried to get up, but in doing so was lifting his head off the ground. As the punches continued it forced his head to smash into the ground/concrete causing the cuts on the back of his head.
This caused GZ to scream for help.
John: "The guy on the bottom, who had a red sweater on, was yelling to me, 'Help! Help!'
TM realized he had to stop GZ from drawing any more attention, so he used his hands to cover GZs mouth and nose.
Now that the punching had stopped, GZ was able to scoot up on thr ground enough to get a hold of his pistol. GZ pulled his pistol and TM tried to get it away from him. GZ was able to fire off one shot, but TMs hand on the slide of the gun caused it to not chamber the next round.
TM fell immediately on top of GZ as he had been straddling him. GZ wiggled his way out from TM leaving TM face down on the ground.
BTW: I dont believe one iota of the "girlfriends" (Crumps) story.