It does not matter why he got out of the truck, and you can't prove what he could or could not recall on a dark rainy night.
It does not mater what he knows of the laws. I got A's in many classes that I couldn't tell you the first thing about now.
The physical evidence supports the theory that Martin initiated the physical altercation. Jentel testified that she believes that she heard Martin say "get off" after hearing "grass sounds" whatever those are. Of course she never mentioned this in any of her initial interviews with the police. Nor do we KNOW what the context of that statement is, especially since there is no evidence that Zimmerman was ever physically "on" Martin, only the opposite.
Let me get on top of you after breaking your nose (by the way, if I punch you and break your nose, you won't find ANY blood on my hand afterwards, because you won't start leaking until after I am no longer touching you. Simply the way it works)and bounce your head on the ground a few times and see if you THINK your life is in danger or are able to count how many times your head hits the ground. Legally it only matters if the jury believes that Zimmerman reasonably THOUGHT his life was in danger. As for your characterization of "trace" amounts and lack of Z's blood on M, It all depends on where Martin grabbed him, hair, ears, shoulders, There really wasn't enough bleeding by either of them for this to matter much.
What happened prior to the physical altercation really doesn't matter much unless you believe (in spite of all the physical evidence to the contrary) that Zimmerman initiated the physical confrontation because they are legally two separate unique events.
Possibly verbal elaboration that is fairly standard in all witness testimony and not that vital. He could also be referring to bushes that were 20 feet away. The emphasis you are placing on this is disproportionate.
If you wear a gun, you are constantly conscious of where it is locate. Any motion towards that portion of your body is immediately thought to be an attempt to reach for your weapon. Extend your hand toward the hip of a police officer some time and check his nigh-unconscious reactions. All Martin would have had to do was place a hand on his hip and Zimmerman would have interpreted that as a motion toward his weapon. What Zimmerman reasonably BELIEVED, at that moment,is rather key here, not what Martin was actually doing, or could even possibly do.
Did Zimmerman spin his story? Probably. Did Jeantel? Yeah, most likely, Witness statements are NEVER 100% correct. Heck one "ear" witness said, in court, that there were multiple gunshots (there was only 1), is that person a liar too, or just suffering for poor recollection, like every other flawed human.
The PHYSICAL evidence is the most telling, and the least subjective. All the damage was done to Zimmerman, no damage was done to Martin (except for the gunshot wound). This leads to the conclusion that Martin was the aggressor in the physical altercation. The next key decision is if Zimmerman (as a matter of law) provoked that physical altercation. There is no objective evidence that he did (Jeantel is subjective), but abundant historical evidence (Zimmermans previous communications with the police)showing hus unwillingness to confront other people in the past under similar circumstances. On this point the evidence is either a wash, or favors Zimmerman (textbook reasonable doubt). Next we come to the "imperfect self-defense" that we covered under other threads which may, or may not, come into play here if, without any reliable evidence, you think Zimmerman initiated the physical attack.
I'm sorry you find yourself unable to emotionally agree with the verdict, but it was COMPLETELY proper.