What, you didn't see the police video just 30 minutes after? Blood easily cleaned up. No visible bruises, cuts, walking normally. All that after your vicious attacks and repeated bashing.
But we all know a black dude approaching you justifies self defense in your mind, so I guess not surprising you keep forgetting those video evidence and clinging to your Zimmerman said....
So the injuries weren't bad enough eh?
Keep in mind that video resolution was really poor. It is meant to show the basic events of comings and goings in the areas those cameras cover... it is not meant to look closely at injuries on a specific individual at varying, but always substantial, distances from each camera.
I'm sure if GZ had known about them ahead of time he'd insist they leave all the blood on him so it'd show up on those cameras and satisfy you more.
From my perspective, we know from the cell phone picture of the back of his head just after, and the close up high res photos of his face with numerous scratches, abrasions, gashes, cuts, etc... that he was being beaten. You can claim it wasn't a bad enough beating but when you're in the dark, in the rain, with a 6'3" stranger straddling you, on top of you... trying to cover your mouth as you scream, help isn't coming and the one guy who looked like he might help just went back inside his house and called cops who were already on the way.... and locked his door.
Well, let's just say that is a situation which could make whatever injuries you were enduring seem a lot worse.
More importantly though, GZ says TM went for his gun. I believe him because why else would GZ shoot then... when either help, or witnesses to any wrongful shooting if it was going to qualify as one, were closer than ever? Why not shoot much, much earlier without giving Trayvon the benefit of a minute plus to rethink what he was doing, and going to such great efforts to involve a third party by screaming? The missing piece of the puzzle which explains why he shot then, was TM going for the gun.
Now, maybe TM didn't intend to use it on GZ... maybe just take it away from GZ so it couldn't be used on him. Maybe TM was so f'd up on purple drizzank lizzeaan SON that he wasn't behaving how he might normally and might've shot him. Regardless, it was reasonable for GZ to fear that he would.