Wilson's testimony starts on page 196
http://www.washingtonpost.com/blogs/liveblog-live/liveblog/live-updates-ferguson-grand-jury-decision/?id=e0bed8b5-98ab-442c-871e-cfb1d7bd7bceWilson had asked them why they could get on the sidewalk and out of the middle of the street when Brown asked him "what the f*** you going to do about it"?
Then Wilson tried twice to open his car door and both times Brown slammed the door.
Brown used his fist to hit Wilson in the face and Wilson tried to deflect it. He felt trapped in the car and grabbed Brown. He said he felt like a five year old holding onto Hulk Hogan.
Brown hit him again and there was lots of tussling inside the car. Wilson pulled his gun and told Brown if he didn't back off he was going to shoot him. Brown grabbed his gun and said; "your too much of a ***** to shoot me". Then they fought over the gun and Brown jabbed it into Wilson's hip. Wilson thought he was going to get shot as he could feel Browns finger in the trigger guard. Wilson got the gun pushed down into the seat and tried twice to fire it, and twice it just clicked.
^There is a lot of detail in his testimony, well worth reading. A lot of stuff happened inside that car before he even got out.