No proof in that except Zimmermans word.There is proof Zimmerman was following Martin in his car and got out of his car to follow Martin.Zimmerman was the aggressor
All the physical evidence and other information backed Zimmerman's account of the situation.
If I hear a noise outside my house, and I call 911... and they tell me it would be best to wait in the house and wait for the cops (who are 15 minutes away), but I decide to go out my front door to the public sidewalk (while armed) and see what is going on -- I am legally NOT the aggressor when a criminal thug attacks me and I put rounds in him in a stand-your-ground state. Same situation, just using a home instead of a car.