Regarding confusing punching with grappling, John states:"in my first statement that I made, I did say that he was hitting him from on top, um, because that's what it looked like. I mean he could have still been hitting him, or he could have been trying to hold him down, you know."
Interesting is the word "still" - it sounds like John knows that George had been hit.
Keep in mind the following:
- there was no "static holding GZ in position" at that point in time. John describes movement while he observed them struggling.
- when trying to stay on top of a person that is struggling to get up/escape, you need to keep clearing the bottom person's arms, and alternatively post your own on the ground to keep balance - almost a swimming motion.
- from John's perspective (behind Trayvon), the act of struggling to stay on top of GZ would (especially with poor lighting) look similar to Travyon striking George. In either case, there would be movement of Trayvon's arms/hands. John was clear that he couldn't quite see where or how Trayvon's hands were being used.
In this context, his statement about ambiguity makes perfect sense.
Even a casual fan of MMA, like John, should understand a mount reference. It's a term used multiple times by announcers describing the action most rounds.
Since John could see Trayvon's upper body I don't think that statically holding GZ in position could be confused with punching. To me, John's testimony strongly suggests some violent activity on Treyvon's part. I think John admits that he can't distinguish the tactical motive for that activity.
I suspect the defense interview will help clarify John's observation. Its too bad we don't have a video of John's "Bam,bam, bam" interjection.