[Revolting cat!]

Zimmerman is as believable as all the other witnesses? When he's an, uhm, interested party? You're making me laugh, so tell us why. Here's and interesting bit from the report you linked:

Lamilla and Cutcher described Zimmerman pacing around the body, following the shooting, and disputed that there was any indication of a fight.

[VeniVidiVici]

Lamilla and Cutcher described Zimmerman pacing around the body, following the shooting, and disputed that there was any indication of a fight.

There is another eyewitness that claims Martin was on top of Zimmerman and Zimmerman was screaming for help.

[PapaBear3625]

Lamilla and Cutcher described Zimmerman pacing around the body, following the shooting, and disputed that there was any indication of a fight.

Police report from the scene says Zimmerman has a bloody nose and a wound in the back of his head.. This is consistent with it being Martin who was on top beating Zimmerman, rather than the reverse. There is also no report of Martin's body displaying any injuries other than the single shot which killed him.

In the linked article, Lamilla is describing that AFTER she hears the gunshot, she claims to see Zimmerman on his knees above Martin.

This is consistent with the following scenario: Martin is on top, beating Zimmerman (accounts for Zimmerman's broken nose and wound to back of head, probably from hitting the ground after being attacked). Zimmerman shoots Martin. Martin drops. Zimmerman starts to get up, first rising to his knees, which is the scene Lamilla describes.