In my humble opinion, when the perps were outside and fleeing, while the waitress's actions seem heroic said actions were not very smart.
As David pointed out, she was not defending HER property, were she defending her property there still would be legal ramifications..
Discharging a weapon in public endangers folks and surely and issue could have occurred...
I recall about 3 years pasted in Florida, I believe, that a woman received a 20 year sentence, for firing a warning shot into the ceiling of her home in and effort to scare away her ex husband that she had a RO against, he was in the home an attempting to harm the woman's Daughter..
If I recall she exited the home and retrieved a gun from the garage, than entered the home to assist her daughter, she fired 2 rounds into the ceiling...
I haven't heard much more about her plight, last I heard she was sentenced to 20 years.. I hope the same fate DOES NOT befall the waitress..
My .02
Regards