That's why you should never fire a warning shot!!! IF you're not scared enough to shoot the perpetrator, you're not scared enough to use deadly force.
Most people have never had to use deadly force to protect themselves or their families. When these people sit on a jury, this is what many believe since their only experience came from what they've watched on TV or at the movies
That being said, I hope she's able to get a new trial because this is a BS verdict. But, if she had actually shot the loser, his past should have had more bearing on the case.