There are a few things we know for fact based on testimony from George, Jenteal, Expert Witnesses:
1) Zimmerman was following Trayvon.
2) Zimmerman showed intent to follow Trayvon through his phone call with the 911 dispatcher ("these assholes always get away," "fucking punks," "have the police call me, and I'll tell them where I'm at," etc)
3) Zimmerman asked Trayvon "What are you doing here?" (this rules out Zimmerman's statement of being jumped from behind.
4) Trayvon asked, "Why are you following me?"
5) Zimmerman's injuries were consistent with being hit in the face 1-3 times, and hitting the back of his head 1-2 times on the ground/concrete.
6) There was only one drop of Zimmerman's DNA on Trayvon Martin, on the lower part of his hoody.
7) There was no DNA of Zimmerman on Trayvon's fists, and the laceration on Trayvon's hand had not broken the skin or bled, and was on his left hand. Trayvon was right handed.
8) Zimmerman's holster was behind his back, at his waist, under his jacket (removing the gun from the holster while being pinned to the ground would have required some significant strength from Zimmerman, if the gun was retrieved while they were on the ground, as Zimmerman suggested. This begs the question; if Zimmerman could lift his body with enough strength to pull free his gun, why didn't he have the strength to push off Trayvon Martin, or hit him?)
9) Zimmerman had no defensive bruised/wounds on his arms, hands, etc. There was not a single drop of Trayvon's DNA on Zimmerman at all.
10) Trayvon was on the phone with Rachel Jenteal up to one minute before police arrived.
11) Zimmerman is lying. This is backed up by the facts above.
If this was truly a case where Zimmerman felt justified in using self defense, why is he lying so much?