The video has no sound. But watch. Sure -the guy shouldn't have shoved the shooter..BUT...
The argument was loud. Watch people walk in. EVERYONE who parks and is seen turns and watches. The argument is 100% loud and causing a scene. So the guy with the gun is obviously having more then just small discussion.
In fact -it was loud enough that the victim was alerted to it and came running out of the store to protect his family. Yes...
Dont forget - you are in a store and you hear that some guy is standing at your car yelling at your GF, her 2 kids under 6, and your 5 year old son.
What would you do?
You run out and see someone yelling at them and standing RIGHT above the door...
TO be honest -if the victim had a gun and opened fire - wouldn't he have ALSO been able to claim "Stand your ground". Couldn't he say he was worried for the safety for his family as this clear aggressor was.
So lets give a high level recap. A family (Woman of 2 kids under six, her Boyfriend, and his son of 5) stopped to run into the store and pick something up. She parked in a handicap space. (Shouldn't have done it -but it wasn't even "parked". she was standing there. Im thinking most of us have done something like this.
Guy starts yelling at her. Loud enough to draw the attention of bystanders and the father in the store. Farther comes out and sees someone fighting with his loved ones in a aggressive way standing above the car door.
He shoves the guy away from his family. Not the best choice, but not one completely unreasonable.
The guy pulls out a guy - and quickly the other guy backs up. The threat (if there ever is one) is over. He shoots anyway. Its murder. Not only that - but based on the actual statue - the sheriff is wrong not to charge him.
Stand your ground includes a presumption of justification in a dwelling, residence, or vehicle. This was in none of those. So there is no presumption of justification. He is still legally ok to use stand your ground, if he can show that he "REASONABLE believes that such force was needed to prevent death or serious body harm". Because it was outside in a parking lot it is not presumed to be ok. He (The shooter) needs to show that it was reasonable.
Being pushed away from someones car and family to me, does not equal a "Reasonable" assumption that his life was in danger or that he risked more harm.
Edit - ALSO - Reading the actual law. there is this "The justifications for use of force will also not apply where the evidence establishes that the defendant initially provoked violence against him- or herself.".
In my mind -watching the video - the defendant did initially provoke the violence. Dont stand over a car yelling at a women with 3 preschool kids in the car and be shocked when someone pushes you.