First, I will be snipping quite a bit. I'm after a few select statements and I do apologize if you find this out of order but having multiple people quote it makes little sense to me.
I didn't know they were going to allow the 2nd, 3rd or 4th hand stories to be allowed into "evidence." If so, are the Martins also going to get to tell the story as they know it? It would only be fair. Also, you have to keep in mind that people can have misunderstandings. For example, BG said that Mr. Martin was sitting on the porch and Mr. Zimmerman just came up and shot him. She didn't understand something somewhere, obviously.
If you ask me, this supports Mr. Zimmerman because he doesn't say they were rolling around on the ground trying to rip each others clothes off. He states he was hit, he fell to the ground, Mr. Martin was on top of him slamming his head into the cement, his mouth/nose was covered and Mr. Martin went for his weapon. To me it seems logical that there wouldn't be a whole lot of ripped clothes, etc, given the story as it's told.
After reviewing the enhanced photo, which is much more clear than the blurred video you linked, I still can't be sure there isn't a bandage. I see a smudge mark, but that could be indicative of a bandage that is full of blood and starting to drip. I do see two bump type anomalies slightly higher of those marks also. Without the reports I wouldn't say either way, personally.
Another problem is that the body was no where near the cut-through that you're speaking of. Whether you take Zimmerman's story or your own the body would've been near the cut-through if he "cut Martin off." Both stories have Mr. Zimmerman falling near the place that they met and the confrontation happened.
I'm not sure about you, but I watch a lot of "funny videos" where people fall down due to various things. Not very many videos do you see of people falling back as if they're doing a nose dive. Maybe if he lost consciousness after being hit and his body locked up, but he never states anything about actually losing consciousness from what I know. I don't know enough about the picture from 3 minutes after to speak of it confidently.
So now he's in a backwards nose dive (unconscious?), holding on to someone.. and his knees don't buckle? I don't buy it.
I'm not going to fully speculate, but I think Mr. Martin was trying to get the weapon out of his hand based on the information I discussed earlier with another member here about a new round not being chambered. If he's trying to get the gun he's not trying to get away.