What I recall reading is, she said the call dropped before she heard anything other than words being exchanged.
If Zimmerman initiated the fisticuffs, she should have heard quite a lot, judging by what turned up on the 911 audio, recorded from much further away.
On the other hand, if Martin pressed End before setting about messing up the Man, she would have heard just about what she heard.
We'll see if "critical race theory" impacts this case--will testimony from black people count for more than testimony from non-black people? It could be considered "turnabout is fair play" because in the antebellum South testimony from a slave couldn't be used against a white person.